jd62

Could it detect that there's a difference between front wheel and rear wheel speeds?

Gord96BRG

Not true - some older traction control systems only used the brakes, but many often had a mechanical implementation of a method to reduce throttle as well (even Ford's TC on the 95-96 Contour did this). Nowadays, with drive-by-wire throttle systems, the DSC and TC systems DO reduce throttle and possibly also timing to reduce power going to the rear wheels. The RX-8 DSC and TC systems DO use throttle and timing control in addition to brakes.

Regards,
Gordon

8_is_enuf

Wing -- What kind of mileage are you getting?

Wing

22-20.5MPG NEVER had anything under 18MPG

All city would be 19MPG, my best was a long highway trip 22.5MPG

Can't get better than that it seems, I did hit redline a few time in that good tank.

This last tank I've been hammering it all the time and it seems like I'm on track for 19MPG (all city).

T-von

Hey guys, he did menchen that he had over 5,000 miles. Could it possibly be the ecu finally allowing the engine to run at its full potential with the DSC & TCS off? Rudenauer, could you do a couple dyno runs with DSC & TCS on and off and post results?

TDS

I just did a quick test for freeway driving mileage. Round trip 94.5 miles on freeway. I got a record 19.4 MPG. After 1600 miles I haven't gotten any better that 16 MPG.
I will try the traction shut-off and post results.
Thanks for the suggestion.
My tail pipes still seem very sooty. Does anyone else have the same?
This week I'm going in for a 1000 mile check-up. My Mazda dealer has advised me that the oil change is not covered under warranty. This seems wrong to me.
For a company ready to buy back my car at my choice, you'd think they would easily cover an oil change for free.

f1michel

Ok guys, like wing said we both have the exact same car, bought in 2 different provinces and we basically get the same fuel economy. I have no idea if DSC and all traction control makes it worst but it seems logical that if you drive it real hard most of the time it will hurt the mileage using the DSC. If you drive it moderate or easy i don't see how it affects the fuel consumption since there is no wheel spin and slide involved.

I am revving up my engine for the next tankfull, (filled up yesterday) and i will see what sort of mileage i get. I am now at close to 6000Km on it and it drives fantastic without the traction control. Up here it will be valuable during the (very)cold season but besides that time i really don't care much for it. (a good thing since i don't have it :-) )

FEBtch

I cannot comment on the DSC full off mileage, because I just tried it today. The car did seem to have much more punch over 6000. But I CAN testify to the milage - I have been keeping track for the last 4000 miles, and have been averaging 17.8 with DSC ON. I will start the DSC full off soon - but I know I will have a hard time keeping it on the road (I have a very heavy foot).

f1michel

Don't worry, this car is VERY fun to drive without any help from electronics. Hell you might even become a better driver , just learning to have your right foot do the traction control.. :-))

TJRX8

Filled up today and started running with DSC full off. So far about 75 miles, should know in a couple days.

I did find one problem with turning it off, after getting used to it always being on and correcting for a heavy foot in the turns. When trying to accelerate from a stop at an intersection and shifting into second 3/4 into the turn your backend will whip out in a heartbeat. And even though you easily beat the BMW 330 to the next light, you didn't look so good doing it. And the surprise of it will make your heart race just a little.

FEBtch

That is either a BIG turn or an early shift - I usually don't hit 30 until I am out of the turn.

TJRX8

Probably a little of both Eight lane wide intersection and shifted around 7K.

canzoomer

You are right on this one Gord.
I was intrigued after reading the post on this.
I admit I am being a bit of an insomniac tonight ( OK, so it's almost 4 a.m. here!)

I have not turned off the DSC completely up to now, just the first stage a couple of times.
Car was in break in mode mostly, and I figured the difference between the short push, and holding the button for complete disable would not feel much different.
So, went for a spin. needed to buy smokes anyway ( used my Zippo as my radar detector is plugged into the place where my cigarette lighter USED TO BE!) {dig}

Anyway, to cut to the chase:
1) It has a HELL of a lot more power with it completely off.
There is a marked 1/4 mile on a back road about 5 minutes from my house. I live at the edge of the city, and paved secondary roads are close.

At 3:30 a.m. the traffic is non-existant, so I hope people will not think of this as "street racing"
First time I have done hard burn-out style runs on this car so far.
Took a stop watch ( it is a big one I wear around my neck as a soccer ref). I did my clutch drops at 6,000rpm and on the non-DSC runs I used moderate clutch slip to achieve some smoke without the rear end sliding out.

Did 3 runs with it on the first disable mode (DSC light warning):
15.5
15.4
15.2
Average: 15.36
I am probably within a couple of tenths accuracy manually running a stop watch..

Turned the DSC completely off (car on wavy tracks light on the dash).
Drove at 80kmh/3000rpm for about 3 clicks to cool the engine off.
Tried again:

15.1
14.8
14.9
Average: 14.93

Now, I grant this is NOT the same as a real track, with a tree, and perfectly accurate time equipment.
Still, I can see almost a half second improvement.

Also, with it right off, there is a definite feel of more power on the "butt dyno" above 5,000rpm.
Common belief is that it takes about a 10HP gain to feel any difference, so that sounds about right, as I DID feel that it is faster. My butt dyno guesses that it is putting maybe 15 or 20HP more down with the DSC right off.

It did not feel "snaky" in hard cornering under power. There is one corner on that road that is a fairly tight bend.
I have never been able to get the RX-8 to four wheel drift up to now, as I have had the DSC on, and it does work in conditions like this.

I was able to achive a drift in 2nd under hard power. No fuss, it was perfectly predictable transition from traction to slide with no surprises.
I could modulate the oversteer with throttle and recover quite easily.

So, unless you are on really crappy road conditions, it seems to me that turning this off almost all the time is the best thing to do for most people..

As for gas mileage, this week shall tell.
My mileage has been pretty predictable and constant so far, so if there IS a difference, I will likely see it..

rx8daniel

I agree most here should be / are able to drive a car such as this without computer assisted aid in keeping slides under control. For winter or rainy weather I think it's a good thing to use - just in case.

Magar

Interesting posts from everyone. Makes for great reading. Thanks.

As a side FYI, I got 21.4 MPG on the highway....a 300 mile trip (yes...running on fumes)....the second long trip was shorter about 220, and still got 21.1 MPG. I filled up after each trip at the same station, on the same pump. Not truly scientific, but a good indication of potential. I have not gotten (even is city driving) anything less than 17 mpg, but haven't been real aggressive with RPMs (usually shifting at about 6k). Good luck on all the tests. I'm going to try the butt dyno later today with TCS off too.

Charles Cope

If the DSC/TCS is a mileage/performance killer, wouldn't it be true that anyone that has a base RX-8 (not equipped with DSC) would get better mileage?

Wing

So, here's an interesting question.

If when you COMPLETELY turn off the DSC the Traction Control light, lights up as canzoomer has mentioned. Is it REALLY REALLY TRUELY TRUELY disabled? I mean come on, the light is on, the DSC is OFF, but what about the TCS??

Welcome to my world guys, I have a GS, no TCS no DSC, the car is plenty damn fast, and my gas mileage as mentioned is in the 20-22MPG range, no lower than 18-19 even in the city!

And it is fun to drift, just don't over compensate like I did once and go into a sliding ballet.

8_is_enuf

Is there nobody on here with MAzda engineering who can confirm that this MAY be the issue, or exclude it from the possibilities?

f1michel

i,m like Wing here, car has no traction gyzmo, rides like a bullet and is so much fun to drive i'm at 6000KM sharp in 35 days.

Why pay 3 gran extra for a car that's less .... :-)

Kidding guys

RodsterinFL

another point is the way the engine is set up to deliver fuel. According to my Yamaguchi book, if you keep the RPM's below 3500 when you shift you will use only one injector and conceiveably less gas.

Rudenauer

T-von,

I will try to get this car to a dyno sometime next week. I am extremely interested to see what kind of power variance (if any, a tip of the hat to skeptics) the car is putting out with the system on and off.

Rudenauer

So Canzoomer, if your mileage improves, do you think that you might rethink your decision?

mmjames

What is strange is that we pay extra for those features and it seems better times are if they are off. Something else to consider.

Simple question How do you turn the DSC and TSC back on, while driving. Must you turn off the car first each time?

Digisan

Yes, you must turn the ignition off if you disable them both to get them re-enabled.

If you only turn off the DSC then you can re-enable it while driving.

POD

Is there anyway you can completely turn the DSC and TSC off for good, so you don't have to bother with it the next time?