I recently drove an 07 M6 with the 7-speed SMG Transmission. I like the car but was not pleased with the transmission lag when paddle shifting. Is this shift lag common to the SMG?

 

Which Drivelogic mode were you using?

Greg A

 

During the test drive we used various modes but even with the Drivelogic set at 5 there was considerable shift lag. I was also wondering if you lift a bit on the throttle when paddle shifting if that makes a difference.

 

Put in in S6

 

S6 is the fastest shift. If it still shifts slower than any human, the clutch might be slipping.

 

My boss has a 2007 M5, and I notice the lag. My friend has a 2008 135i and the automatic transmission with paddles seems faster than SMG. It's just ridiculous, it's so quick.

 

You need to be in S6 for the fastest shifts, but even in S5 my shifts are faster than yours. Btw, I never lift off the gas between shifts.

 

I don't lift off the gas either, you shouldn't but maybe your having clutch issues.

 

Thanks for all the comments. I am really bothered by the shift lag. I have read many posts regarding the SMG transmission. Some love it and some hate it. I have to believe something is not right with this car's transmission though because the lag is just too pronounced. I also see that BMW has come out with a new DCT transmission. That seems to indicate some dissatisfaction with the SMG? The car I drove had less than 14K miles on it. Downshifts were almost instantaneous but up shifts were very slow even when driven aggressively. I had expected something on the order of the PDK. At this point I think I will pass on the car purchase. I like everything about the car except that pronounced shift lag.

 

I test drove an M6 last year and noticed the same thing you are writing about. It basically turned me off (and I drove that car for a long time, in all sorts of road conditions - i.e. highway, local, etc.) and since then have read and talked to enough people to know that its part of the transmission make-up and hence what keeps the M5 and M6 in my mind, a great M car.

I have the M3 with the M-DCT and there is no comparison between it and the SMG. M-DCT is what SMG should have been, go for a test drive to see for yourself. You won't have any questions after driving one.

 

Thanks for letting me know you had a similar experience. I am off to the dealer tomorrow. I have been debating on the 2007 M6 vs. new M3 for a daily driver. I really liked the M6 but that SMG tranny was not right. I will test drive a DCT.

 

People rarely answer this question properly and it's frustrating to read...

The higher the RPM you shift at, the faster the shift. Shifting at 2-3k rpm can take close to half a second while shifting in S6 @ 8000rpm will slam it in 60ms (something like that anyway).

It's one of the quirks of SMG, I don't like it either but the visceral feel of shifts at redline in S6 more then make up for it for me and many others. SMG is a funny transmission, I love mine but it did take some getting used to.

I'll always love the transmission that does the best job (in terms of acceleration) ala DCT, however I do think I will sorely miss the violent kick you get with SMG, closest you can get to a manual feel without the stick and 3rd pedal.

 

Put it in the sportiest manual mode and turn on the MDM mode. This is the only way to drive this car.

 

I think you hit it on the head, its a quirk. Something that makes you accept the car's faults. I rather have a car that does what I want it to.

I don't know, when I'm hit the gears with the DCT, you feel some 'kick', or as my brother said when he drove it (with a smile and a giggle): "I love how when you up-shift at the high revs, it actually lurches forward. wow"

 

In the end it's still an awesome driving experience and that's what counts. When you drive it aggressively, it does do what you want.

The kick in the M5/M6 on S6 shift makes passengers smile with glee, it's just bloody awesome. I hope DCT does have some kick as it is the future but from what I have heard, it's nothing compared to the kick of SMG.