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Old 12-07-2003, 12:00 PM
HUMMM 3 HUMMM 3 is offline
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Mein Auto: 02 M3 Coupe, Topaz/Black
Originally Posted by marksmith
I have a new M3 w/ SMG (which I love) but I have a question :
#1: It is often my habit w/ manual cars to roll to a stop in neutral. I do this w/ my SMG by clicking the shift lever L to "O" (or neutral.) This seems to work fine & appears to be perfectly OK for the SMG programming. Any reason (mechanically) not to do this w/ an SMC car? (FYI: I do not always like the rolling stop SMG downshifting programming w/ the car in Auto-mod: the shifts can be a bit abrupt or pre-mature in settings 3-4.)
#2: While driving in the manual mode (any setting 1-5) is it advisable/OK mechanically to roll to a stop and allow the SMG to downshift "automatically" (as opposed to downshifting manually & thus use the engine to brake the car?) I don't always want to use the engine to act as a brake (SMG's tendency to downshift in slow, passive city driving. ) In the manual mode the car will roll to a slow stop and shift down automatically at the last moment from 3rd to 2nd & then first w/o my intervention. Does this create a problematic engine load? The car never seems to stall, struggle or lug in this context.

My experience w/ the SMG has been very positive but I do not always "agree" w/ the programming choices relative to city driving situations IE: In my usual manual setting of #4, upshifts are perfectly paced but downshifts from 3rd to 2nd are best in setting #3 (smoother transitions.) I wish there was a way to "save" this preference in say a "Daily commute mode".
Thanks for your SMG feedback!
First, rolling to stop in neutral, I don't believe will harm the car other than cause additional brake wear. (By the way knowing how to slap the transmission into neutral is a handy thing to know - its the equivalent of "in a spin clutch in") I do very little bumper to bumper gridlock type driving so I haven't developed a strategy for it. I leave the Drivelogic switch in 5 and always drive in the manual mode. The automatic mode never felt like it could accomplish crisp shifts unless you really stand on it (not many opportunities for that).

As for coming to a stop I try to anticipate it beforehand. Example: I'm city driving in third gear, I come to stop sign/light, I brake, manually shift to second, (approximately 15 yards from the stop) and as soon as the "2" light stops flashing (gear engaged) I manually shift to first. Once you get this technique down you'll be able to come to stop smoothly without throttle blips, jerks and clunks and be ready to go again. I have also found that downshifting manually from speed, say, on a freeway off ramp you don't aways get a throttle blip if you coordinate your braking and your shifts right. This technique is handy when you don't want attract attention from the cop hiding at the top of the off ramp.

I have found that occasionally when, say, rounding a corner in third slowly and I want to shift to second the transmission may not want to shift right away, but by manually using a light throttle blip it shifts smoothly right away. This also works in heavy traffic when you've just shifted into second and you need to get back to first.
2002 E46 M3 Dinan S3-R