I have been driving manual transmissions for a long time and I frequently use what I call 'engine break' i.e. shifting down to slow down the speed...like I am going in 4th gear and I shift down to 3rd and then to 2nd to slow down in conjuction with using the regular breaks. Its not like I am punishing the engine all the time ... just gradual down shifts ... making sure the RPM doesn't go high while down shifting. I hope you guys understand what I am trying to say here. It has become kind of a driving habit for me. My question right now: Is this driving style harmful for an engine?

And MORE SPECIFICALLY how does this driving style affect a ROTORY engine viz. the apex seals etc..

Please enlighten me! as I haven't owned a rotory before.

what ur doing is called transmission braking, not engine braking. ur using the gears to slow u down.

ur putting more wear and tear on the more expensive part(the transmission) then on ur brakes. brake pads/brakes are much cheaper and easier to replace then ur transmission.

Hi tribal,

I understand that its not creating any problems for the brakes, actually the transmission braking would create lesser wear and tear on the brakes.

What parts of transmission get damaged?

Is it harmful for the cylinder/pistor or in rotory case the housing/apex seals etc???

Maximus

I don't think there's anything unique in your style of driving a stick - this is what 99% of stick drivers do, and I can't believe it creates any excessive engine wear. It will certainly lengthen the life of your brakes, and leave you in the correct gear to take off swiftly once you stop deccelerating.

Go with your instincts, and have fun

Originally posted by Maximus
Hi tribal,

I understand that its not creating any problems for the brakes, actually the transmission braking would create lesser wear and tear on the brakes.

What parts of transmission get damaged?

Is it harmful for the cylinder/pistor or in rotory case the housing/apex seals etc???

it doesnt hurt ur engine. the transmission doesnt get "damaged", ur just putting more wear on it. u rather wear out the less expensive parts(brake pads) then ur transmission

Rexor,

Thanks for your input. When u are down shifting and using it to slow down the car what would be happening inside the rotory with respect to the intake/exhaust ports?

This same question came up on Car Talk a while ago. They recommended using the brakes.

Originally posted by m477
This same question came up on Car Talk a while ago. They recommended using the brakes.


Hi m477,

Any details that you remember?

This is one of those topics that have been debated forever, and on every forum I have ever visited. And there is never any agreement between the two camps. Some people say they never do it because of wear and some people (myself included) have always done it. I have never had any issues due to doing this and as long as you are rev matching, clutch wear is minimal. I would prefer to always be in the proper gear (even if there is 'alleged' extra wear) than to be in the wrong gear if I need to get moving quick.

I never had any problem downshifting to slow me down. I use it everytime and no problem. Gradually downshifting wont hurt, but going 4th to 2nd gear.

I rarely do it. When I do, I rev match. I'd rather replace brake pads than synchro's.

Brake pads $50
Engine $5000
.
A gearbox never slowed anybody down. Engines sucking vacuum slow you down.
Throttles shut, engine turning 7000rpm, no fuel, no air, big vacuum to suck whatever lubrication you have into the combustion zone, to be burned 'blue' when you get back on the gas........
No, it's probably not the best situation to put your engine in. (This is when 'two-stokes' sieze, after a hard acceleration, you cut off the flow of cool air and freshly evaporated fuel, at the same time doubling the revs.) Remember, the wankel is actually a 'two-stroke/four-stroke' it has no idle time like a four stoke.
Even if you wear out your rotors as well as your pads, it is 5% of the engine rebuild cost.
.
Drive any way you like, but be aware of the wear & tear.

Ray.

I think where the confusion comes in to play with this topic is some people are referring to "slowing down" and manuevering through traffic vs. coming to a stop. As for downshifting to slow down in the process of driving and manuevering, Rexor is correct in that 99% of us probably do it, while when coming to a stop, some people may take the previous action to an extreme (IMO) and do it every time they are coming to a stop. As mentioned before, brakes are much cheaper than mechanical wear and tear regardless if it's the engine or the tranny.

As for me, I do downshift on occasion say if I'm in traffic and I know going down just one gear will slow me down enough while still being at a decent RPM, but at the same time, I almost never down shift while coming to a stop. I just put it in neutral and coast to a stop. If the situation changes while slowing down, the correct gear is only a snick away.

One of the negative aspects of using engine braking is that in a standard 2 wheel drive you will be applying this braking force to only 2 wheels, not all four. This can upset the balance of a car. On a front wheel drive car this could cause the car to oversteer and spin iif you are cornering.

I've done that once and it wasn't much fun. Missed everyone else though, so just completed the 360 and continued on my way.

Like everyone else I still use engine breaking, but not quite so aggressively as I used to;)

Originally posted by Rexor
I don't think there's anything unique in your style of driving a stick - this is what 99% of stick drivers do, and I can't believe it creates any excessive engine wear.
It most certainly is NOT what most stick drivers do; for one thing most stick owners have figured out brakes are a LOT cheaper to replace than a clutch, and that's essentially what you are doing by downshifting - saving your brakes at the cost of vastly increased clutch wear...

As a wise instructor once told me:Gears are for going; brakes are for slowing.

This is called 'throttle braking' try this on a diesel and you get nothing, no braking [got jake brake]

Anyway the throttle by wire system has a program for 'drag torque regulation' that controls how much (or little) the throttle should remain open when you lift off completely

using throttle braking on a front wheel drive car will cause understeer, using throttle braking on a rear wheel drive will cause oversteer, but since the Rx-8 will have a torque sensitive differential that oversteer will be partially mitigated.

I have always downshifted when slowing. Is there any extra wear and tear? Who knows? I've never had to replace an engine or tranny. None of my car friends have had any extra tranny/engine service that could be related to engine braking. And we're not talking about gentle driving with just a bit or engine braking drivers here, they all are hard driving/engine braking/heel-toeing/road racing/autcrossing people.
In fact, they just checked my tranny fluid at my last oil change and they said it was clean as can be. People gotta remember we're not talking about slamming into 2nd from 5th at highway speeds and getting that nose dive affect here. It's actually very smooth and done along with using the brakes. I wouldn't be worried about engine or tranny wear, but just be sure you are rev matching or the clutch will get extra wear.

Maybe my car will not get to 300,000 miles, but only make it to 250,000...or maybe it will. Who cares... I doubt anyone will still have the car then. To me this is a non-issue realistically. It's sort of the same thinking that some of my parents friends still have about how you can't have a 4cylinder car vs a 6 or 8 because higher revving cars can never last as long - too much wear and stress. Well I would bet on a Honda lasting longer than a Buick anyday.

Again, this is one of those issues that have been going on forever, but will never be resolved. Just drive safely and enjoy yourself!

I myself used to engine\throttle\tranny break all the time, now I only do it when I need to stop very quickly especially on the freeway. I find it faster to engine break then trying to break hard during sudden stops\slow downs. I hate anitlock brakes. It always gives me that jerky feeling. If I have to speed again then I wouldn't have a problem since I'm at a lower gear. But as for wear and tear I really don't think engine breaking would wear down the tranny all that much faster. If anything it'll probably just wear down the clutch a little sooner.


But engine breaking all the time will just consume more fuel.

Maximus,
The first thing you should do is to fully understand how the manual transmission works. If you have doubts, go to www.howstuffworks.com, they have animations and pictures to show you exactly how it works.

Let me just briefly illustrate what happens when you just down shift to a lower gear. For example, you are happily cruising along at 60MPH, you engine turns the clutch, the clutch drives the layshaft, the layshaft drives the gear in the transmission ....etc etc.... all the way to the wheels. Everything is happy. Now you decided to down shift, all of a sudden you are making all the machinery in the drive train works a little bit backwards (in terms of power transfer), the gear is now forcing the layshaft to spin faster and therefore the clutch, needs to spin faster and therefore the engine got start turning faster. This is why the engine goes "rooooam" and the rpm goes up even with the foot off the pedal. Since you are not putting any extra fuel in engine, the engine is trying to slow down but the rest of the drive train is forcing it to move faster than it is suppose to. Anyhow, you are basically created friction and resisitants in your drivetrain to slow down the wheels.

Now old school drivers will tell you that the mechanics of drive train are built to transfer the force from the engine to the wheels and NOT the other way around. Nowadays, many people thinks the engine and the parts are now a lot more durable and what drives what, it really doesn't matter since you are still putting force on them anyway.

Bottom line is if you want to downshift to slow the car, make sure you are rev matching. That way, at least you are saving your clutch. If you can, double clutch and rev match, this will further reduce the wear and tear on your drivetrain (layshaft gearing, sychronos, etc ).

The best advise I can give you is that if you know how it works, you will know how to maintain it.

-Smoker

Thanks everyone for posting ur experiences with engine/transmission/throttle braking.

Doctorr's response was the closest w.r.t. to rotory engine.

To recapitulate dont worry too much about it generally and specifically with the rotory. At the same time dont punish the engine too much, match the revs, of course avoid down shifting from 5th to 2nd etc. in trying to come to a complete top. Just use the this kind of braking, if that is your driving style, in conjuction with the regular brakes. Go with your instincts.

Does that summarize it all?
(more discussion is welcome however!)

Originally posted by BillK
...saving your brakes at the cost of vastly increased clutch wear... Gimme a break... You don't wear out the clutch when engine braking, unless you are slipping it excessively (as in having it half-way in/half-way out).

---jps

Originally posted by Sputnik
[B] Gimme a break... You don't wear out the clutch when engine braking, unless you are slipping it excessively (as in having it half-way in/half-way out).

Any time you use the clutch, it wears.

Go through the gears both up and down and you will be making 2x the shifts, and wearing the clutch more by definition.

Add the fact that most people cannot rev-match precisely on a downshift and most downshifts tend to wear the clutch a bit more than upshifts do.

Bottom line is that engine braking per se does not wear the clutch, downshifting back through the gears on your way to a stop does.

I sell Trannie parts and Do repairs. I have a pretty good grip of how a trannie works. Down shifting and actually using the break peddle to slow down seems to come up once in awhile.

And as Tribal Azn has stated ... all down shifting does is wear your trannie down. Such as the synchro gears, and the clutch assembly. After all everytime you change gears the synch gear have to adjust to the engine rpm, and everytime u clutch, the throw out bearings have to release and the re apply and the clutch surface gets worn.


Break pads, are easier to use no? even to replace them is less work and less costly. Break components such as the Master cylinder and junk rarely go out. only things that ever need replacing is the pad ad the rotor. pads cost 40-80 bucks OEM (20 bucks after market) rotor can be re-surfaced and if you use it right. last forever.. cause the i havent change rotor on my any of my cars yet.

Trannie parts cost as follow. typical import car synch/bearing kit runs you 120-200 bucks (OEM, not dealer but LUK) and the clutch also runs you typcially 100-150 (LUK, OEM) not only are the parts more expensive, the labor to drop the sucker is a lot more. typicall labor on standard trannie is 200-400.

Conclusion. Use the break, more work for your feet, but saves in the long run. But then again its less engaging of a driving experience.

Originally posted by TheSaCK
I sell Trannie parts and Do repairs. I have a pretty good grip of how a trannie works. Down shifting and actually using the break peddle to slow down seems to come up once in awhile.

And as Tribal Azn has stated ... all down shifting does is wear your trannie down. Such as the synchro gears, and the clutch assembly. After all everytime you change gears the synch gear have to adjust to the engine rpm, and everytime u clutch, the throw out bearings have to release and the re apply and the clutch surface gets worn.


Break pads, are easier to use no? even to replace them is less work and less costly. Break components such as the Master cylinder and junk rarely go out. only things that ever need replacing is the pad ad the rotor. pads cost 40-80 bucks OEM (20 bucks after market) rotor can be re-surfaced and if you use it right. last forever.. cause the i havent change rotor on my any of my cars yet.

Trannie parts cost as follow. typical import car synch/bearing kit runs you 120-200 bucks (OEM, not dealer but LUK) and the clutch also runs you typcially 100-150 (LUK, OEM) not only are the parts more expensive, the labor to drop the sucker is a lot more. typicall labor on standard trannie is 200-400.

Conclusion. Use the break, more work for your feet, but saves in the long run. But then again its less engaging of a driving experience.

thats what i was trying tell everyone but no one seems to listen.

im taking auto shop class at my high school and my teacher told us all about it.

we also learned all about brakes. we did brake pad replacements and brake jobs and they r unbelievably easy to do. i can only imagine how hard(and expensive) it is to repair or replace a damaged tranny.

i've downshifted since the day i got my truck 8 years ago and have yet to have any problems with my clutch or synchros. i just rolled 100k miles yesterday evening too. tho, i never downshift to 1st, that's just too hard and way unnecessary. i do see how it is more wear on the gears but it's not as bad as you think.

the way i drive is if i need to slow down i'll downshift but usually only when i reach about 5mph above the beginning of the current gear im in...say i'm in 5th, i'll rev match 4th gear in when i hit 50mph and then begin/continue braking...after that i just use the brake the rest of the way down. tho, i typically use 2nd to slow down a lot too for the appropriate speeds anyhow. downshifting all the way through the gears is too dangerous for me as it's really easy to lock up the rears in my truck.

bleh i've forgotten where i was headed with that, at any rate, my .02 is i'd rather be in the correct gear (just incase) and deal with whatever more wear it comes with since i can't tell the difference in wear. i've just taken apart 2 trannies this past week too btw, both of which were 30+ year old 4 speed saginaws and i honestly could not tell the difference in wear.

All the worry warts should just buy a 4-speed V8 instead of a 6-spd low torque car. That way you never have to shift and minimize wear and tear.:D

Bottom line is if you want to downshift to slow the car, make sure you are rev matching. That way, at least you are saving your clutch. If you can, double clutch and rev match, this will further reduce the wear and tear on your drivetrain (layshaft gearing, sychronos, etc ).

Question about double clutching... I don't really understand why it's supposed to help in a vehicle that has synchros. What does it accomplish, and is it done just like in a vehicle that has no synchros?

Originally posted by Synergy


Question about double clutching... I don't really understand why it's supposed to help in a vehicle that has synchros. What does it accomplish, and is it done just like in a vehicle that has no synchros?

with the clutch depressed, and the shifter in neutral, there are gears that are now free spinning in the transmission and all the load of bringing the layshaft and the gear you want to get into is put on the synchros. when you double clutch you are using the motor to adjust the lay shaft speed and if you do it right the gear you are trying to get into will be spinning at the correct speed relative to the drive shaft and you will slip right past the synchros.

when you go into gear you know how you feel that notch on the way in? that's the synchros. you won't feel it if you are matched perfectly and you will just slip right into gear.

Originally posted by BillK

It most certainly is NOT what most stick drivers do; for one thing most stick owners have figured out brakes are a LOT cheaper to replace than a clutch, and that's essentially what you are doing by downshifting - saving your brakes at the cost of vastly increased clutch wear...

When you use words like "most", I assume you have actually spoken with at least 51% of the worlds manual transmission drivers... Hmmm?

Hi guys,

Since we're in the subject of breaking, I too have my own driving habits. Would some advise from you guys if my style/how I drive is bad or ok.

Alright, when I know that I'm coming to a slow traffic either it's slowing down to a stop or slowing down to pick up speed again, I have this habit of shifting the gear to neutral, all I do is use my break to slow the car down. So if the traffic comes to a stop fine, I'm already in neutral. But if the traffic were to pick up speed, I'd just shift to the right gear and go.

What would be the disadvantage of my driving habit?

Cheers

Well,M-ster, no problem if youre not rear-ended, no fun to be rear-ended and pushed into a busy road section. As for not using your brakes, well, my oncle had a Nissan Sunny and he was engine braking all the time. So much that got stuck and when he need to panic brake they didnt work too good.
So I advice to use both your brakes and handbrake, since they operate better if theyre used now and then...

m-ster...really the only disadvantage of braking in neutral is that you're not in gear...and that split second to rev-match into gear and get going again could make the difference. although the chance of being in said situation is miniscule, it happens.

and about the increased wear on the drive train...i've had my toyota truck for 8 years now, 106k miles on it and i've engine braked/downshifted since i've gotten it. i've done nothing but gas/oil/air filter and one set of tires so far. even still have the original battery in it. sure it's more wear, but given the life span of the car...

there are situations where one would be much better off using engine braking, maybe not so much with the rx-8 but with other cars that do experience much more dramatic brake fade. imagine driving down the mountain back from a ski resort or something and riding the brakes constantly for 2 hours, that gets dangerous

then there are 18 wheelers...but i guess those guys are in a different league of engine braking cause they have some flap or something they can pull that will slow the truck down with engine compression or something to that effect.

Originally posted by BillK

It most certainly is NOT what most stick drivers do; for one thing most stick owners have figured out brakes are a LOT cheaper to replace than a clutch, and that's essentially what you are doing by downshifting - saving your brakes at the cost of vastly increased clutch wear...

If you rev match properly there should be no clutch wear whatsoever! Hell, in one of my cars I could go all the way up and back down the box without touching the clutch, grinding the gears or even stressing anything.... I just dropped it into neutral with no load so it slips out of gear easily... then match the revs and grab the new gear... Don't try this at home kids, if you get it wrong you'll grind your gears nicely....

Folks, I am new to this forum but have been driving a variety of standard transmission cars for over thirty years. I regularly use downshift to slow the vehicle. I have gotten over 100k out of my clutches on several occasions and have never had any engine damage. I am the son of a truck driver and this is a very common practice for truckers also.

I have seen this type of conversation in other forums and in the end no one has ever provided any documentation that downshifting is anymore stressful than acceleration. If folks are this worried, they need to drive automatics.

Originally posted by Twin 8s!
If folks are this worried, they need to drive automatics.

Hmmm... I think twin8s brought up something interesting. I've never own a automatic car, only driven some occasionally. When you apply break in an automatic car (of course you'll be using the break), does the car automaitcally uses engine break as well, or it just jump to the appropriate gear (either 1st to a stop or speed match to pick up again).

This question will leads to: if it's good to use engine breaks, won't the automobile industries would have made the automatic transmission doing engine breaks when the car is break to a stop/slowdown.
But if there's already engine break in the auto trans, we've got the answer.

I think the other question is ... Do you watch your diet? How bout... Do you get enough sleep?

This is a sports car! Drive it, have fun! If you cause an additional 1000 miles of wear in 150,000.... so what.


ZOOM ZOOM

Oh... by the by....


I think burnout demo in the video section is far more damaging than downshifting....

If you rev match properly there should be no clutch wear whatsoever! Hell, in one of my cars I could go all the way up and back down the box without touching the clutch, grinding the gears or even stressing anything.... I just dropped it into neutral with no load so it slips out of gear easily... then match the revs and grab the new gear... Don't try this at home kids, if you get it wrong you'll grind your gears nicely....


I had an 86 camaro that went from third to fourth real easy without clutching. Just pulled it gently out of third, waited about 1/2 seconds for the rpm to drop and applied slight pressure into fourth. It would slip right in, no noise, no grinding, no wear that I knew of.

Hmmm... I think twin8s brought up something interesting. I've never own a automatic car, only driven some occasionally. When you apply break in an automatic car (of course you'll be using the break), does the car automaitcally uses engine break as well, or it just jump to the appropriate gear (either 1st to a stop or speed match to pick up again).

This question will leads to: if it's good to use engine breaks, won't the automobile industries would have made the automatic transmission doing engine breaks when the car is break to a stop/slowdown.
But if there's already engine break in the auto trans, we've got the answer.

In every automatic I've owned, the tranny stays in gear. (e.g., it stays in 4th until you are stopped.)

To those who do use engine braking, I'm having a hard time visualizing what you mean.

What situation are you talking about: e.g.,

* going 60 mph and stopping for a red light?

* going 80 mph on a freeway and slowing down for a 45 mph exit (or for slow traffic ahead?

Personally, I rarely use engine braking and would find it hard to believe that "99%" of manual drivers use it on a daily basis. Especially when the brakes on the RX8 are so effective.

Please excuse me if my question sound silly as I am a newbie in driving manual. Let's say I am driving at 40 mph in 4th gear, and I see some traffic ahead where I have to slow down to about 15 mph. What is the proper way to change gear in this scenario? The way I do it now is use the brake to slow down to around 15mph and change to 2nd gear while I am almost done braking....rev match if needed.

Please excuse me if my question sound silly as I am a newbie in driving manual. Let's say I am driving at 40 mph in 4th gear, and I see some traffic ahead where I have to slow down to about 15 mph. What is the proper way to change gear in this scenario? The way I do it now is use the brake to slow down to around 15mph and change to 2nd gear while I am almost done braking....rev match if needed.

That's what this whole debate is about. Some (including me) would do exactly what you do, brake then downshift to 2nd. IMO, it is more efficient does less wear to the transmisison, clutch, and engine. And, perhaps most importantly, tells people behind you what you're doing (i.e., your brake lights tell people you're slowing down). Others would down shift to 3rd to slow down the car, then downshift to 2nd. I'll leave it to those drivers to explain why they do that (I tried that earlier today and engine braking just doesn't slow the car that much.)

out of some strange habit, i rev my engine up right before I let out on the clutch when I downshift. I guess this way the engine in a sense is what is slowing me down....it doesn't slow me down as much, but it sounds cool......lol.

chad

I myself used to engine\throttle\tranny break all the time, now I only do it when I need to stop very quickly especially on the freeway. I find it faster to engine break then trying to break hard during sudden stops\slow downs. I hate anitlock brakes. It always gives me that jerky feeling. If I have to speed again then I wouldn't have a problem since I'm at a lower gear. But as for wear and tear I really don't think engine breaking would wear down the tranny all that much faster. If anything it'll probably just wear down the clutch a little sooner.


But engine breaking all the time will just consume more fuel.

If I understand you correctly, if you want to slow down from 70 to 50 because of traffic, you'll use your brakes. But if you're slowing down from 70 to 0 because of a red light, you'll use the engine because it is "faster".

To me, that is totally counter-intuitive. I can guarantee you that the RX8 will stop faster with the actual brakes than with engine braking. So how is it faster or easier?

And I also don't understand why you hate anti-lock brakes? It seems that you don't like the pulsing. But I almost always drive too fast and brake too late, but I have yet to even activate the ABS. (I've yet to drive it in the rain, one of the joys of living in CA is the lack of rain). If you don't want the ABS to activate, brake a little bit sooner and not quite as hard.

I think this engine braking method is really impractical. That is why they invented wheels brakes in the first place. I just clutch, neutral, cruise, step on brake pedals like how the car makers intended.

The only time I'll be doing downshifts is when taking a corner or speeding up fast (dropping 2 gears down) without "engine-braking" the car.

I can't believe I read through this thread. Everyone "Engine Breaks", whether they think so or not. It does not matter if it's a manual or an automatic. You let the engine compression do the breaking for you.

Lets say you're going 70mph on a highway. To state the obvious, you press the gas going up the hill. Then, at the crest of the hill you back off. Now, let's say it's a good 5% grade down the other side. You're probably not on the gas right now. And, hopefully, you're probably not riding your breaks down the other side. If you are, and you're pushing any weight (like a car pulling a trailer or a big rig), say goodbye to those brakes... really quick.

So then, since everyone is "engine breaking"... why does anyone think downshifting while coming to a stop is anything worse? It's been said enough here regarding clutch wear. Just rev-sync on the downshifts.

I once took a car in that I had since the day it came off the lot to have it's brakes done. The shop asked me why I thought my brake pads should be replaced. I said... look, the car has 180,000 miles on it and has never had it's brake pads replaced... and it's freaking me out... so I think it's time they just get replaced. They did... and let's just say I never got down to the medal. Oh, and at that time, the clutch still hadn't been replaced. The car was sold at just over 200,000... without ever needing a clutch. Did I downshift at every possible stop... Darn right I did. Did I use the brakes? As little as possible, and usually while doing heal-and-toe action.

BTW - Automatics do downshift - though often more delayed than those of us driving a manual transmission would choose. Brake slowly and watch the tach... you'll see it.

So then, since everyone is "engine breaking"... why does anyone think downshifting while coming to a stop is anything worse? It's been said enough here regarding clutch wear. Just rev-sync on the downshifts.


I'm not talking about the wear and tear. My concern is practicality. Yes, I let my foot off my gas when I see traffic is slowing down. But why would I down shift, especially if the light is red and I'm going to be at a complete stop anyway? I also fail to see how it is any smoother.

So here's the questions.

*You're 60 mph and the light in front of you turns red. What do you do? What do I do: I take my foot off the gas, then brake at an appropriate moment which will stop me smoothly and safely before the light. I see no reason why I should down shift from 6th to 2nd.

* You're going 80 on the highway and you approach your exit, which you take at 45 mph. What do you do? I would brake to 45 mph, then downshift from 6th to 3rd or 4th and take the corner. Would you not hit your brakes at all and go 6 to 5 to 4 to 3 to take the corner? Wouldn't that take longer than just pushing the brakes a little?

I am the only one who reads Road and Track?! Since at least the early 70's, when I began reading R and T, they have insisted, with great justification, that a driver should not use the transmission to slow the car. Use the brakes; that why they are on the car, to slow it. The transmission is there to transmit power to the drive wheels. Brake components are cheaper to replace than transmission components. I hate the sensation of the car being slowed with a non-double clutched down shift - it makes no sense and only the rear wheels are being braked. Why not use all four wheels for braking and save wear on the driveline? Maybe some folks like the feeling of loading up the drivetrain with a shift... I dunno why though.

I am glad you enjoy your subscription to Road and Track. I am sure you read their adds in the back for enlargement and augmentation also.

I found the following comments from you interesting.... "I hate the sensation of the car being slowed with a non-double clutched down shift - it makes no sense and only the rear wheels are being braked. Why not use all four wheels for braking and save wear on the driveline? Maybe some folks like the feeling of loading up the drivetrain with a shift... I dunno why though."

The next time a truck comes up behind you at a stop light jump out and tell the driver that you do not like the way he/she is slowing down their vehicle.

In closing, this entire thread is idiotic and now ... boring. People downshift. If you do not want to, DON'T. There is no data showing excessive wear as the direct result of downshifting. Downshifting is an option available to people that drive a standard transmission vehicle and has been used forever. It does take a little skill to use it efficiently and so if you do not like to do it... DON'T. If you are unable to master the technique, DON'T do it.

If it keeps you up at night.... buy an automatic.

I am glad you enjoy your subscription to Road and Track. I am sure you read their adds in the back for enlargement and augmentation also.


It's not just Road & Track that says it. Every performance driving book I've ever read (Bondurant, Barber, Prost, Speed Secrets) say that brakes are for slowing the car down, not the engine. The use of the engine to slow the car down is an old technique developed before the advent of disc brakes when it was necessary. It's not necessary anymore.

Downshifting doesn't seem to serve any purpose. It doesn't help braking appreciably. It is less fuel efficient. It requires more work. It is louder. Since you are the expert, what are the benefits of downshifting to slow the car down?

Good grief...

I am not espousing that downshifting should be used as the primary way to slow your vehicle. Jeesss... Relax!

If this gets you going, don't feather your clutch on a hill, don't accelerate to hard, and for heaven's sake do not spin your tires because that causes enormous stresses on your clutch, drive shaft, transmission, suspension, and more.... Those 0-60 times that everyone is messing with cause a lot of wear and tear on your vehicle so lets not do that (besides not the car’s forte anyway).

For that matter, make sure to stay under 50 MPH. That way you will be able to achieve the maximum fuel while facing lower wind resistance and extend the longevity of your vehicle.

Please ensure that you avoid all traffic routes that have stoplights or stop signs as this will force you to use your clutch and potentially result in excess wear.

Do not forget to avoid turns as this will shift weight to one tire or another and might result in wear.

Maybe the best thing to do is to build a nitrogen containment tank and store your vehicle there for posterity.
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Or… you could remember the commercial (ZOOM ZOOM), and just drive.
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Wow. Way to bring back a thread from the dead. Kinda a silly thing to start arguing about again a year later, don't you think?

I downshift. The harder I drive, the deeper into the brake zone, the harder I downshift.

And visa-versa, to the point that I rarely, or ever so slightly, downshift with my babe on an evening cruise.

It's a very natural thing to do. I agree that everybody does it. Take your foot off the gas and you're doing it, unless you clutch every time you let-off the gas. I doubt that.

Go to a road race, or just watch one on tv. Going into the turns, they all do it - very hard. It's a rudimentary thing to have to know how to do if you want to race. Tell me I'm wrong, I'll tell you that you know nothing about entering a turn. It's just a rudimentary thing, very much so.

Oh yeah, I never wore-out a tranny or a clutch, and I keep my cars for a very long time, I'm not the kind that changes cars when they buy a new pair of shoes. :cool:

Absolutely.

And by the by.... Bondurant and Barber TEACH IT.

Ok, Ok... Engine braking puts extra wear on expensive parts instead of cheaper parts. If your main goal is to save money, then use the brakes -- that's what they're for. While you're at it, why not buy a set of nice hard rubber tires that will last 80,000 miles -- it's cheaper right?

To me, part of the sports car experience is engine braking. I think it's fun, so I do it about 2/3 of the time I guess. You're not going to break anything, just wear things out a LITTLE faster. And it really is just a LITTLE faster -- I've never had a clutch last less than 100,000 miles and I always drive "spiritedly" (is that a word?)

Wow. Way to bring back a thread from the dead. Kinda a silly thing to start arguing about again a year later, don't you think?
Most of us weren't HERE a year ago to express our opinions. Isn't this kind of discussion what the forum is FOR? It doesn't seem silly to me. :confused:

Go to a road race, or just watch one on tv. Going into the turns, they all do it - very hard. It's a rudimentary thing to have to know how to do if you want to race. Tell me I'm wrong, I'll tell you that you know nothing about entering a turn. It's just a rudimentary thing, very much so.
Downshifting does not equal engine braking. They aren't downshifting to slow the car down, they are downshifting to get the car into the optimum gear when power gets applied.

Also, that is a totally different situation than what this thread is talking about, downshifting for a red light on the street. The reason I revived this thread is to find out why you should downshift to slow the car down.

Absolutely.

And by the by.... Bondurant and Barber TEACH IT.

I have the Bondurant book and took the Barber class. They don't teach it. They teach putting the car in the proper gear to apply power through the corner.

E.g,. you can find a link to the time attack video somewhere on this forum, where a test driver took an RX8 for a lap around Laguna Seca. The first corner is after a long straight where he is going about 108 mph and has to take the corner at 43 mph. He downshifts from 4th to 3rd to 2nd. But he isn't downshifting to slow the car down, he is downshifting so that when he gets back on power, he is at 6000+ rpm in 2nd gear instead of being at 3000 rpm in 4th.

Guys-I guess since I am in mid-50 age I was used to decent but not great brakes. However downshifting gets me ready for roaring around next curve or corner or aiding in stopping. I probably will not change-in fact with the few automatics that I have owned I tended to manually downshift these as well and I never broke one nor had any problems. If it was so bad why do they make manumatics?

Thanks for vent.

Bob

HOLY BAT GUANA!!

Have you all forgotten why you own an RX-8???

Have fun!!!!!

Soooo to recap the recent entries above....
- Truck drivers downshift to slow their vehicles
- Race car drivers downshift... some say to slow them dowm (oh no... say it ain't so)... I guess their trannys are just trashed.
- I downshift… there I have come out of the driver’s seat
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And lastly GUSMAHLER... do think the driver you reference slowed at all when then downshifted? Let me help the answer is "yes". If he as any good at all, he used any means possible to slow the car and prepare for the next turn.

Well... gotta go, I feel the need to drive a winding road and based on living in a free country.. downshift any damn time I want.

Downshifting does not equal engine braking. They aren't downshifting to slow the car down, they are downshifting to get the car into the optimum gear when power gets applied.

Also, that is a totally different situation than what this thread is talking about, downshifting for a red light on the street. The reason I revived this thread is to find out why you should downshift to slow the car down.You know nothing about entering a turn. There. I warned you. :p

Downshifting slows you down for a turn just like downshifting for a red light on the street. It applies decelerating torque to the drivetrain, to the drive wheels.

It also usually gets the car into the optimum gear for when power is to be applied out of the final apex, or if the light turns green before you come to a complete stop.

Usually though, if I know that the light is going to stop me completely, I knock it into neutral and apply the brakes, why bother. Is that what you wanted to know?

Soooo to recap the recent entries above....
- Race car drivers downshift... some say to slow them dowm (oh no... say it ain't so)... I guess their trannys are just trashed.

And lastly GUSMAHLER... do think the driver you reference slowed at all when then downshifted? Let me help the answer is "yes". If he as any good at all, he used any means possible to slow the car and prepare for the next turn.


They aren't downshifting in order to slow the car down. They are braking to slow the car down. Does the downshifting slow the car down? Of course it does! But 90+% of the slowing down was caused by the braking. They slow the car down by braking. They downshift to prepare for the next corner.

We're just arguing semantics now. Have fun on the road!

It's not just Road & Track that says it. Every performance driving book I've ever read (Bondurant, Barber, Prost, Speed Secrets) say that brakes are for slowing the car down, not the engine. The use of the engine to slow the car down is an old technique developed before the advent of disc brakes when it was necessary. It's not necessary anymore.

Downshifting doesn't seem to serve any purpose. It doesn't help braking appreciably. It is less fuel efficient. It requires more work. It is louder. Since you are the expert, what are the benefits of downshifting to slow the car down?

Engine braking is very important when descending long steep mountain roads. Otherwise you are riding your brakes and are risking control of the vehicle due to brake fade or even complete loss of brakes. There is only so much energy you can put into the brake pads and rotors and that can easily be exceeded on a long steep road.

This is an interesting thread...

I'd like to make a clear distinction between engine braking and downshifting (or transmission braking, or to be most accurate, "clutch braking")..

To clarify:

Engine braking- Reducing the speed of the car by using the opposing forces generated by the weight and friction of the engine and transmission against the general the inertia of the drive train, (beginning with the moving parts of the engine--ie pistons or rotors, crankshafts, etc-- to the driveshafts, and through the transmission gears). Engine braking occurs while the car is in gear, not during the downshift. So as an example, you're driving down a very long slope or hill and decide against "riding" the brakes. . So, instead, you downshift correctly (rev the RPMs to match the engine to prevent unnecessary wear on the clutch), and then let the car roll in the lower gear, letting the "weight" of the moving engine parts naturally keep the car from increasing in acceleration. This is the ideal situation that the AUDI drivers manual suggests when to use engine braking.

Clutch braking- Very different from engine braking... It's slowing down the car by way of downshifting and letting clutch slow the car down. So, instead of using the brakes, the driver downshifts and engages the clutch without matching the RPMs. The clutch bears the load to slow the car. The end result is not only deceleration, but clutch wear and noise. Afterwards, once the car is completely in gear, engine braking may or may not occur, depending on whether or not the drive continues to let the car "roll" while in gear.

Novice drivers confuse this "clutch braking" with "engine braking". The inexperienced drive frequently clutch brakes accidently when downshifting because they aren't used to revving the engine before going into gear or don't rev it enough, or have poor timing. This can be even more tricky for them approaching a turn, when the car is decelerating at the same time.

Speaking of shifting at turns, seems people handle this differently also.

For everyday driving, I tend to drop the shifter into neutral as I approach a turn, then still before the turn I put the shifter into a lower gear with the clutch still disengaged (down). As I turn, the car begins to deccelerate, at which I give it some juice and engage the clutch slowly out of the turn. I think most experienced people drive like this on an everyday basis.

But then there's the more controlled and less used method, where the clutch is already engaged in a lower gear before the turn.. Being already in gear gives the driver more control over the car as they aren't hassling with the clutch during the turn. I rarely use this method because I'm it requires more work. They simply concentrate on their steering and accelerate easily out of the turn. But this means you have to downshift while deccelerating, and to do it smoothly (without engine braking) it takes more effort as well as more experience with the car. It also uses more gas, since you're revving after AND before each turn. In racing situations, this is done VERY fast, ala "heel-to-toe"..

So which method do you use?

Or if you have a different method, I'd like to know.

HOLY BAT GUANA!!And lastly GUSMAHLER... do think the driver you reference slowed at all when then downshifted?

Yes . . . because he was depressing the brake pedal really hard, and wanted to be in the right gear to make power when he came out of the corner. Downshifting WHILE braking to ensure you are in the proper gear is correct. Downshifting to slow down WITHOUT braking is incorrect, and causes UNNECESSARY wear and tear on your powertrain.

Yes, wear and tear happens, especially when you drive fast and enjoy the car. However, what sense does it make to abuse the car? You're saying, "Hey, pushing the car to its limits will strain it anyway--so why not just beat the crap out of it?" The answer is "Because you dropped a lot of money on a wonderful car, and you should take the best possible care of it, even if you enjoy it to the fullest."

Peace
policy

P.S. "ENGINE BREAKING" = BREAKING THE ENGINE
"ENGINE BRAKING" = DOWNSHIFTING WITHOUT USING THE BRAKES

Squidward - some good stuff there...

I "engine brake", although I do like the inertial feel of a "clutch brake", and do so every once in a while. Maybe a blend? Bringing the engine up, but not to the matching rpms? Say, up to 4000, clutch brake to 6000?

I always (I think?) get her into gear before the turn. Engaging in the middle of a turn can be upsetting.

True, hard racing requires hard braking - using the brakes. However, saying that downshifting doesn't slow the car down, the brakes do it - is neglecting that engine/clutch braking does indeed assist in slowing the car down, it helps reduce heat build-up and wear of the brakes - a little. It helps keep from locking it up - a little. Sure, watch how fast a racecar goes without brakes - it doesn't cuz it can't slow down well enough for the turns by just downshifting. But downshifting will help keep a racecar from loosing its brakes, and will help decelerate better by assisting - a little.

In everyday driving, it's alright to engine brake, it's alright not to. Who cares? Clutch braking is definetly more detrimental, so its use should be restricted for long life of a lot of drivetrain stuff.

First off I'll say that I am definitely in the camp supporting use of the disk brakes for reducing speed, and that "clutch braking" definitely CAN cause premature wear of the clutch. This argument has gone all over the place to the point that people aren't even arguing about the same thing anymore. Squidward hit the nail on the head in describing "engine braking" versus "clutch braking". Those of you who claim that "clutch braking" isn't any worse than using the disk brakes--your argument seems to make the assumption that most people can match engine speed before and after a downshift. Maybe some of you are great at doing this, but I'd guess that 95% of drivers can't do this perfectly. The result is that the clutch IS being worn at a faster rate than a driver who doesn't "clutch brake". The conclusion I'd draw from this is that you shouldn't "clutch brake" unless you are very capable of matching engine speed before and after a downshift.

Somebody was questioning how an automatic transmission handles these situations. The answer is that this argument doesn't apply to an automatic transmission, because all downshifts occur with the torque converter clutch unlocked. This means that there is only a fluid coupling between the transmission and engine, thus no friction material to wear down. Automatic transmissions have set downshift speeds at any given throttle position. Therefore, downshifts do occur as the vehicle slows down, but the high damping in the torque converter hydraulic fluid absorbs most of the energy so in many cases the downshifts can't even be felt by the driver. Also, automatic transmissions never shift to neutral unless the driver moves the shift lever. First gear is always engaged when the vehicle is stopped and in drive--that's why the vehicle rolls when you let off the brake pedal.

Someone asked how to Double Clutch ….instead of typing out a manual I’ll send you to two sites via google search..
http://www.driversedge.com/dblcltch.htm or http://www.felixwong.com/openroad/double_clutch.html

I’ve found that IF you’re going to combine engine/clutch with break pads, it’s better to double cutch instead of just slamming it into the lower gear. Better control while entering/exiting a turn, better control while stopping and you’re ready to accelerate if the light turns or the intersection clears. Do I do it every time I down shift?? Depends on the what’s going on, most of the time yes other times neutral and brake. Personally, like having the car ready to go......that’s why I bought the 8 (a sports car that loves to rev and handles great). Heel toe thing still a little tricky, so if it’s question between braking or rev matching, braking ALWAYS wins...... Anyways that’s my two cents.....everyone has their own driving style, just remember drive within your limits and have fun......zoom zoom.

it doesnt hurt ur engine. the transmission doesnt get "damaged", ur just putting more wear on it. u rather wear out the less expensive parts(brake pads) then ur transmission

Spoken like a true ricer. Keep doing what you're doing :). I wonder why this dude got banned :confused:?

I have the AT and put it in manual mode mostly for the ability to downshift and use engine breaking that i miss most from driving a stick. At a complete stop or almost stop I put it back in AUto mode to allow the automatic to shift up. I feel a lot more in control downshifting to slow then using the brakes alone. The auto transmission seeems to have a control in it to not allow downshifting when engine is too reved up, and the cool paddles on the steering wheel sure make it seem like it was designed for this.

This is common practice when driving a truck whether it be a tractor/trailer (semi) or a farmer's grain truck. Large trucks do the 'engine braking' because of the large heavy load they are trying to stop, plus they are using industrial strength engines to do it with that can take the abuse. The 8 uses a high rev, sport engine in the form of the Renesis rotary. The Renesis is not an industrial strength engine. My vote is to place the wear and potential tear on the brake rotors and not the engine rotors.

Conclusion. Use the break, more work for your feet, but saves in the long run. But then again its less engaging of a driving experience.
It takes more work to rev-match and downshift than to just press the brake.

If you're going down a long steep hill, you should downshift. Otherwise either method is OK and it comes down to personal preference; I almost always rev-match and downshift. It helps me learn the RPM-vehicle-speed ranges in the car and, more importantly, is fun.

Learn to heel and toe. Lotsa fun and probably the best way to slow a car.