Do the throttle settings affect DCT clutch wear?

[Budget M3]

Which of the throttle settings results in the most clutch wear? Intuitively it would seem the Efficient throttle would slip the clutch a little more and could result in greater wear, but I’m just guessing.

Also, is D harder on clutches than manually shifting the DCT? This is my first two-pedal car so am just curious as to what to expect.

[CanAutM3]

I don’t believe the engine setting has much impact on clutch slip. You should ask about what DCT Drivelogic setting people use, because clutch slippage is mostly related to the DCT Drivelogic setting.

In general terms, DCT will slip the clutch more in S1/D1 than is S3/D3 to achieve smoother upshifts and to rev up the engine on downshifts.

Further, I think driving style will have much more effect on clutch wear than the engine setting.

[hlothery]

I agree. I do not like the D1 drivelogic setting, and always set mine to D2, which I find much more pleasant in traffic, and in normal driving. The downshifting this program does often means I do not need brakes while following in traffic, as the engine slows the car adequately, except in very quick stops, and I can let it coast in 1st or 2nd gear without it unecessarily shifting to a higher gear. I suspect S1/D1 would be the most clutch wear.

[Budget M3]

Originally Posted by hlothery

I agree. I do not like the D1 drivelogic setting, and always set mine to D2, which I find much more pleasant in traffic, and in normal driving. The downshifting this program does often means I do not need brakes while following in traffic, as the engine slows the car adequately, except in very quick stops, and I can let it coast in 1st or 2nd gear without it unecessarily shifting to a higher gear. I suspect S1/D1 would be the most clutch wear.

Agree that #2 setting is best for everyday. I do notice a difference between shifting performance from a stop depending on throttle setting though. Efficient seems to slip the clutch a little while Sport completely engages the clutch sooner.

[nicknaz]

I thought with a wet clutch like in dct that slipping the clutch doesn't really matter?

[CanAutM3]

Originally Posted by nicknaz

I thought with a wet clutch like in dct that slipping the clutch doesn't really matter?

Slip is slip and will induce wear. However, the wear is indeed less on a wet clutch setup. This thread remains theoretical as the DCT clutches should outlive the car.

[shortseller]

Another thing to keep in mind as to clutch wear is to not excessively ride the brake during creep mode.

[Budget M3]

Originally Posted by shortseller

Another thing to keep in mind as to clutch wear is to not excessively ride the brake during creep mode.

I was thinking the same thing as I just discovered creep mode two days ago. I’ve been driving in manual shift mode since I got the car (it’s the only way I will even drive my wife’s e46 M3 SMG). Accidentally bumped the shifter into D and was pleasantly surprised to find the car will creep forward on its own in stop n go traffic. Very nice!

[SenorFunkyPants]

Originally Posted by Budget M3

I was thinking the same thing as I just discovered creep mode two days ago. I’ve been driving in manual shift mode since I got the car (it’s the only way I will even drive my wife’s e46 M3 SMG). Accidentally bumped the shifter into D and was pleasantly surprised to find the car will creep forward on its own in stop n go traffic. Very nice!

Creep mode works in manual mode as well...or it does at least in the Euro market.
Tap the throttle and off it creeps...shift to S2 to go a little faster..

[mkoesel]

Originally Posted by Budget M3

I was thinking the same thing as I just discovered creep mode two days ago. I’ve been driving in manual shift mode since I got the car (it’s the only way I will even drive my wife’s e46 M3 SMG). Accidentally bumped the shifter into D and was pleasantly surprised to find the car will creep forward on its own in stop n go traffic. Very nice!

Do you mean without having to apply the accelerator?

If so, and if your use of the colloquial "stop n go traffic" is indeed meant to communicate that you are genuinely bringing the vehicle to a full stop, and depending on what you meant by "creep forward on its own", you may be causing undue wear to the clutches.

As mentioned in the user manual, you must apply the brake firmly when coming to a stop to tell the transmission to open the clutch(es). By contrast, it is also possible to bring the car to a stop with your foot resting on the brake, yet not fully applied. In this case, the DCT may keep the clutch on the edge of engagement which would obviously not be good for the clutch pack.

If you are indeed able to get the car to move forward from a stop on its own power (i.e not downhill) merely by lifting your foot from the brake pedal, you are not applying the brake hard enough to disengage the clutches. Yes, this will allow the car to behave as if it has a torque converter like a vehicle with a traditional automatic does, but it will come at the expense of premature wear.

[Hachima]

Originally Posted by mkoesel

Do you mean without having to apply the accelerator?

If so, and if your use of the colloquial "stop n go traffic" is indeed meant to communicate that you are genuinely bringing the vehicle to a full stop, and depending on what you meant by "creep forward on its own", you may be causing undue wear to the clutches.

As mentioned in the user manual, you must apply the brake firmly when coming to a stop to tell the transmission to open the clutch(es). By contrast, it is also possible to bring the car to a stop with your foot resting on the brake, yet not fully applied. In this case, the DCT may keep the clutch on the edge of engagement which would obviously not be good for the clutch pack.

If you are indeed able to get the car to move forward from a stop on its own power (i.e not downhill) merely by lifting your foot from the brake pedal, you are not applying the brake hard enough to disengage the clutches. Yes, this will allow the car to behave as if it has a torque converter like a vehicle with a traditional automatic does, but it will come at the expense of premature wear.

This is a nice explanation. It also matches what is required to activate the uphill assist to prevent rolling backwards.

[M4Now!]

Originally Posted by mkoesel

Do you mean without having to apply the accelerator?

Low speed assistant (creep mode) is invoked from a complete stop. Tap the accelerator in D or M, and the car will idle forward - you can also upshift to 2nd.

Cheers

[shortseller]

Originally Posted by mkoesel

If you are indeed able to get the car to move forward from a stop on its own power (i.e not downhill) merely by lifting your foot from the brake pedal, you are not applying the brake hard enough to disengage the clutches. Yes, this will allow the car to behave as if it has a torque converter like a vehicle with a traditional automatic does, but it will come at the expense of premature wear.

Thus I believe a reason why BMW is getting rid of the dct, people coming from traditional automatics are not adapting well. So back to a torque converter for the masses.

[Thescout13]

Originally Posted by shortseller

Thus I believe a reason why BMW is getting rid of the dct, people coming from traditional automatics are not adapting well. So back to a torque converter for the masses.

I don't think that's the reason. If so, BMW wouldn't be able to able to move these cars as well as it has. It's definitely a cost thing more than it is a Auto people don't get it. I mean we have had two generations with DCT, that's definitely not it IMO.

[shortseller]

Originally Posted by Thescout13

I don't think that's the reason. If so, BMW wouldn't be able to able to move these cars as well as it has. It's definitely a cost thing more than it is a Auto people don't get it. I mean we have had two generations with DCT, that's definitely not it IMO.

A reason, not the only one to which I’m sure costs are a big consideration along with LT reliability. I’ll also add BMW market focus seems to be drifting from performance oriented to more of luxury sportiness so no need for a dct to satisfy the average driver, this of course just a guess based on production sales numbers I’ve seen. Be nice if they planned to keep the 6 speed manual tranny for the performance minded along with the torque converter auto but I know the 6T is gone as well.

[mkoesel]

Originally Posted by M4Now!

Low speed assistant (creep mode) is invoked from a complete stop. Tap the accelerator in D or M, and the car will idle forward - you can also upshift to 2nd.

Cheers

Right - very aware of that feature. I was addressing the possibility that the OP was instead trying to "creep" using only the brake pedal (like one would with a car that has an automatic transmission) rather than using both the brake (to stop) and the accelerator (to restart movement) as is the proper procedure with the DCT.

Originally Posted by shortseller

Thus I believe a reason why BMW is getting rid of the dct, people coming from traditional automatics are not adapting well. So back to a torque converter for the masses.

If that were a significant issue, and if they really wanted to continue using the DCT, they could program the car to disengage the clutch more promptly when the brake is applied firmly at low speed, and re-engage the clutch as soon as it is released. Some DCT applications already do this.

I agree with the other poster - it boils down to cost. And specifically, it is likely that a dwindling number of potential buyers will consider the DCT a reason to choose a BMW over a competitor's model with a traditional automatic (which all other vehicles in this segment now have). So BMW has probably determined they can no longer sustain revenue by passing the would-be higher costs to the consumer. In other words, equipping the car with the DCT won't bring in any more money than equipping it with the ZF, and might even bring in less.

[Thescout13]

Originally Posted by shortseller

A reason, not the only one to which I'm sure costs are a big consideration along with LT reliability. I'll also add BMW market focus seems to be drifting from performance oriented to more of luxury sportiness so no need for a dct to satisfy the average driver, this of course just a guess based on production sales numbers I've seen. Be nice if they planned to keep the 6 speed manual tranny for the performance minded along with the torque converter auto but I know the 6T is gone as well.

I thought last intel said that the next gen M3 and M2 keeps the MT. I think they are trying to keep their core M cars special.

[shortseller]

Originally Posted by Thescout13

I thought last intel said that the next gen M3 and M2 keeps the MT. I think they are trying to keep their core M cars special.

I think so too, but the manual is barely treading water.

[mkoesel]

Originally Posted by Thescout13

I thought last intel said that the next gen M3 and M2 keeps the MT. I think they are trying to keep their core M cars special.

No reliable intel exists in support of an MT for the G80 M3 yet. We do know for sure that the 3 Series - aside from some low cost models that are not sold in the US - will be automatic only. It is still possible there will be an MT option, but it has not been confirmed via inside information one way or the other yet.

The next M2 is so far off anything could happen. An MT is still a reasonable bet, but it will be the better part of five years before that car comes to market. It'll be a few more years until there is a clear picture.

[Thescout13]

Originally Posted by mkoesel

No reliable intel exists in support of a G80 M3 just yet. We do know for sure that the 3 Series - aside from some low cost models that are not sold in the US - will be automatic only. It is still possible there will be an MT option, but it has not been confirmed via inside information one way or the other yet.

The next M2 is so far off anything could happen. An MT is still a reasonable bet, but it will be the better part of five years before that car comes to market. It'll be a few more years until there is a clear picture.

Didn't say it was reliable, just going off the most recent M3 news posted on the front page of Bimmerpost (https://g20.bimmerpost.com/forums/sh....php?t=1511097) that's all. To me that's the latest intel that created my thought. Time will tell.

[shortseller]

Originally Posted by Thescout13

I thought last intel said that the next gen M3 and M2 keeps the MT. I think they are trying to keep their core M cars special.

MT w/ DCT option coming soon!

[mkoesel]

Originally Posted by Thescout13

Didn't say it was reliable, just going off the most recent M3 news posted on the front page of Bimmerpost (https://g20.bimmerpost.com/forums/sh....php?t=1511097) that's all. To me that's the latest intel that created my thought. Time will tell.

Fair enough. I would just remind that all information right now, as with the example that was quoted in the thread you cite, is from trade publications whose reliability can vary.