Proper downshift?
 

I drive peddle shifter can I use downshift to help slowing down the car? Sometime I go 45km at gear 3, when shift down it choked hard, will that damage the vehicle anyhow?

Use your brakes...that is what they are for....

Yep. My father always told me, "do you want to replace brakes or a clutch and or trans?".

Does the auto tranny have an electronic rev match or does it just jam the next lower gear?

Point taken, brake paddle all the way ~

I enjoy stirring the gears on my 6-speed manual transmission RX-8. With skillful rev-matching, I think any increase in wear would be negligible.

Also, I think it is very appropriate to downshift to a lower gear while descending long, steep grades. Selecting the proper gear and allowing the engine to hold back the car is way better than dragging your brakes. Dragging the brakes in such a situation risks overheating, not to mention excessive wear. And overheated brakes can fail very dramatically.

So, shift away. After all, the RX-8 is a sports car.

With an auto I would slow down first with the brakes and then down shift. Manumatics are no fun.

Exactly what I do; can't resist the temptation not to rev-match because of my Hi-Power Lol.

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I downshift with my auto. The auto won't let you downshift into redline. I useit to slow down the car. No issues here.

He was asking about downshifting when coming to a stop. Using engine braking on downhills and using the appropriate gear is a totally different thing

Also he is driving an automatic.....it will automatically downshift when it gets to the correct RPM...so whats the point

Also he is driving an automatic.....it will automatically downshift when it gets to the correct RPM...so whats the point

I know you mentioned the downhill part but that is the best example of "the point". Go down a mountain in drive and you'll likely be forced to use brakes far more than you should. That said, the auto is likely to shift at a midrange rpm. A high range rpm down shift (done correctly) will slow the car faster, drop gas usage more and save breakpads for when you need them.

No, he was referring to slowing down the car. No mention of a stop. Shifting down to slow down is totally appropriate, particularly for the true sports car enthusiast.

If folks don't want to drive the RX-8 as it was intended, then perhaps it is time find a different car. Maybe a Lincoln Town Car, or something.

As a generality...there is no time in performance driving that you use the clutch to slow down the car......
you are either on the gas or on the brake


...

He is referring to using the engine braking capabilities of the car. Does it hurt the transmission? I don't think so.
I have owned 2 AT's and both were never driven in Auto mode. I was so proficient at down shifting I could rev match like a manual trans from second to first. Perfectly timed blip of the throttle. Ha!
Anyway. I never had a single issue with either AT transmissions. As was mentioned, Shift Away!

Using the clutch to slow down the car means you aren't rev matching. Rev matching doesn't cause clutch wear, and decelerating in gear isn't any more damaging to the transmission than accelerating is. It only gets damaging when you don't rev match and jam it in gear regardless of the difference in speed between the flywheel, input shaft, and output shaft.

Yeah, it's cheaper to replace brakes than it is clutches or transmissions, but it even cheaper not to replace any of them, which is what happens when you drive properly. Even in performance driving, you use a whole lot more brake pad material, but you still downshift through the gears and rev match as you go, you don't just sit in neutral until you are off the brakes and then go looking for what gear you are in.

Your term, "Using the clutch to slow down the car" implies slipping the clutch. During racing, or high performance driving, rev-matching is used. Apparently, you do not understand what rev matching means.

WOW...you are stupider than I thought.....( you were the one that made this personal ;) )

I am more than familiar with proper downshifting...and rev-matching. Thats why I am so adamant about not "using the clutch" to slow down the car. With proper rev-matching you will be using the brakes to slow down the car.....and the transmission is down shifted to ensure you are in the correct gear when you are back on the gas at the apex. If you are using engine braking to slow down you will be way behind anyone driving properly...it is not an efficient way to slow down. You either want to be on the gas....on maintenance throttle..or on the brake. Coasting along to slow down is just loosing time.



The only thing that downshifting an automatic to slow down does is make you look cool....

Well, obviously if you're in a racing situation, the driver would rev-match downshift AND apply braking (heel and toe, anyone?). Since few of us probably actually race, I think it was not out of line for me to assume that the original poster was referring to daily driving. That is why I did not mention braking. Brake away! But rev-match when down shifting.

And I never called you anything like stupid.

Racing or daily driving....if you rev match you will get get almost no braking from the engine. .. so we are basically back to using your brakes to slow down.. most people that downshift to slow down get the deceleration by slipping the clutch.

Only if they do it improperly. I get what you are saying dannobre, but I downshift for >80% of my deceleration time on the street. Yeah, it means I am downshifting way earlier than I would apply the brakes, but that doesn't make my deceleration not work. I typically only actually apply the brakes once I get to the point that a downshift to 1st is next, just because it's usually more jarring than the other downshifts. Over 113,000 miles with my 8, my factory front pads lasted 65,000, my factory rear pads lasted 105,000, my factory clutch lasted 89,000, and my transmission never developed a single problem and never had any excessive wear metal on the magnetic drain plug.

Even on the track, you are still engine braking when you are in gear on the brakes. The engine's braking power is small compared to the brakes, but not non-existant.

People that use the clutch to slow down are doing it wrong, but that doesn't mean that you don't also decel when in gear and off the gas and brake. It's a rather smooth way to drive on the street that doesn't wear brakes, clutch, or transmission appreciably.

Can you get one of those with a manual transmission? And maybe drum brakes, so you do have to gear down to slow it?

Ken

Lol...you need an anchor :)

RIWWP...I see where you are going....not sure its a good idea to shift into first though. It is the most difficult to sync...and basically almost never something you need to do. You can coast down in second almost to a dead stop....and first is usually reserved to starting from a dead stop

Yes, I usually clutch in and use brakes instead of shifting to 1st.

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That is not true at all. Countless times I have tailed some sedan as we drive through and out of our neighborhood. This involves hitting quite a few stop signs. I can tell you for a fact that the car ahead of me is on the brakes long before I am. And how do I do this? You guessed it. Downshifting (with rev-match, of course). And I'm not even racing that little 1.3L engine or slipping the clutch. It all is a very easy technique with no drama. And it works. But do I finally have to use the brakes? Well, of course.

I think something has really been lost here, and that is the fact the RX-8 is a sports car. It is a small car with a small engine. This is in the same tradition of small sports cars from decades ago. Those little small-bore 4-banger engines of yesteryear wouldn't get out of their own way at low RPM's. Mash on the throttle at 2000 RPM and little would happen. But the true sports car enthusiast driver reveled in using the gearbox to keep that little 4-banger "on the boil" which is to say, up in the power curve area that allowed decent performance (such as it was. 60 HP was a thrill).

Our "modern" RX-8 is of similar nature. At 1.3L (1300cc), it is a small engine that makes little power at low RPM. Sure, it will chug along at 2 or 3 thousand RPM, but it you mash the gas pedal at that RPM, you won't get much. Everything around you will leave you in the dust.

So when I'm driving my 6-speed RX-8 in traffic, I shift up or down as appropriate. If I can see that I might need some suds as the traffic situation moves about on the road, I am not above selecting the appropriate gear ahead of time so that little engine is ready to respond. This is the joy of driving a small displacement sports car.

Anyone can drive a big-bore, high torque engine that delivers 90% of its torque at 1800 RPM. Just mash the gas pedal and it goes. Not so with the little non-turbo Wankel engine.

Amen. It's a sports car. Toy as well as transportation...hopefully more on the toy side. Working the gears (even to excess) instead of letting a slushbox do the work for you is part of it.

People kept right on oil painting even after cameras were invented.

Ken