Quote:
Originally Posted by Tom K.
I'm almost positive that the quoted 3.46 differential ratio for the 135i DCT is an error. If that were the case, the car would be turning something like 2,800 rpm @ 60 mph which is higher than than my 128i 6 speed MT in 5th!. IIRC, some DCT owners have reported rpm @ 60 as closer to 2,000 rpm which would mean a FD ratio of about 2.6, given the direct drive 7th gear. Lee123, what is your rpm in 7th at 60 mph?
Edit: The 335is coupe with DCT has a 2.56 FD ratio but the fuel milage is still not greart at 17/24.
http://www.bmwusa.com/Standard/Conte...fications.aspx
And since the OP used the the 335i sedan's Steptronic figures, apparently the DCT extracts a significant mpg penalty in both 1 and 3 series.
Tom |
Thanks, Tom. That explains the discrepancy.
Yeah, the DCT is what sold the 135i to me, but I wish it were more efficient, as the Step, which can extract more miles than the manual.