S Mode and mileage difference on/off

RicerX · 10-28-2014, 10:12 AM

Quote:

Originally Posted by cooltoy

With my previous cars (Audi Quattro coupe, Eagle Talon TSi and Celica GTS) I always rev matched and used the revs to slowdown the car instead of the brakes. But here I have learned that it is bad for the clutch (could be the reason had to get a new clutch for my Eagle Talon TSi way back when), which is more expensive then new break pads.

Don't read this as me being confrontational - I'm genuinely curious, because my line of thinking was different from what you've said. How is rev-matching bad for the clutch?

Reason I ask is because I always felt that rev matching would be better for clutch life because you would have more friction on the clutch without rev matching to get the engine speed to match the drivetrain speed.

The other piece of it is this - the way to save gas driving a manual is clutching into neutral and braking when you need to stop. Coast as much as possible. In the Z, for example, with SRM turned on, if you employ a lot of shifting into neutral, you will use more gas because the car will temporarily hold the revs (using the throttle) until the SRM system recognizes you're leaving the car in neutral. In this case, it's better to leave the system turned off. In any other scenario, it's apples and oranges.

street2soul · 10-28-2014, 01:46 PM

Quote:

Originally Posted by RicerX

Don't read this as me being confrontational - I'm genuinely curious, because my line of thinking was different from what you've said. How is rev-matching bad for the clutch?

Reason I ask is because I always felt that rev matching would be better for clutch life because you would have more friction on the clutch without rev matching to get the engine speed to match the drivetrain speed.

The other piece of it is this - the way to save gas driving a manual is clutching into neutral and braking when you need to stop. Coast as much as possible. In the Z, for example, with SRM turned on, if you employ a lot of shifting into neutral, you will use more gas because the car will temporarily hold the revs (using the throttle) until the SRM system recognizes you're leaving the car in neutral. In this case, it's better to leave the system turned off. In any other scenario, it's apples and oranges.

bingo

cooltoy · 10-28-2014, 02:36 PM

Quote:

Originally Posted by RicerX

Don't read this as me being confrontational - I'm genuinely curious, because my line of thinking was different from what you've said. How is rev-matching bad for the clutch?

Reason I ask is because I always felt that rev matching would be better for clutch life because you would have more friction on the clutch without rev matching to get the engine speed to match the drivetrain speed.

The other piece of it is this - the way to save gas driving a manual is clutching into neutral and braking when you need to stop. Coast as much as possible. In the Z, for example, with SRM turned on, if you employ a lot of shifting into neutral, you will use more gas because the car will temporarily hold the revs (using the throttle) until the SRM system recognizes you're leaving the car in neutral. In this case, it's better to leave the system turned off. In any other scenario, it's apples and oranges.

I think you misunderstood. I wanted to say that using the engine revs to slow the car down, instead of the breaks, might be bad for the clutch. Not rev matching.
I used to pull up to a light without using the breaks and just using the engine rpms (and the clutch) to slow me down, down shifting as low the first gear before stopping with the breaks.

street2soul · 10-28-2014, 03:14 PM

Quote:

Originally Posted by cooltoy

I think you misunderstood. I wanted to say that using the engine revs to slow the car down, instead of the breaks, might be bad for the clutch. Not rev matching.
I used to pull up to a light without using the breaks and just using the engine rpms (and the clutch) to slow me down, down shifting as low the first gear before stopping with the breaks.

i see what you mean. you're talking about wear due to the torsion between clutch and the flywheel while they are engaged, correct? that is a possibility, but I'd think it would be negligible or less stress than while accelerating.

RicerX · 10-28-2014, 03:53 PM

Quote:

Originally Posted by cooltoy

I think you misunderstood. I wanted to say that using the engine revs to slow the car down, instead of the breaks, might be bad for the clutch. Not rev matching.
I used to pull up to a light without using the breaks and just using the engine rpms (and the clutch) to slow me down, down shifting as low the first gear before stopping with the breaks.

I'm tracking now.

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