135i/135is DCT MPG

[c1pher]

I've mainly been commuting around town and getting around 21mpg, but this weekend I drove mainly on the highway and getting almost 29mpg. Is that a fluke? The window sticker said 25mpg so that's what I was expecting. Drove mainly 70-80mph with some city traffic in the beginning over 250ish miles.

[Yeineken]

I usually get that on highway.

BMW is pretty conservative with their numbers.

[c1pher]

Not that I got a sports car for the fuel economy, but still a pleasant surprise.

[zx10guy]

You two must be lucky or my car is just a lush with gas. The best I've ever gotten was 26-27 MPG on a majority highway trip from Murland to Delaware about 160 miles.

[bagekko]

I've had mine 2 weeks and am surprised how I am on the low end of the spectrum. Averaging 18ish on mixed driving, but I am always in Sport & DCT Sport or Manual. Its still better than my M5 where I average 14mpg, but no where near the 23mpg I got in the Z3. I am always a big gas consumer as I drive spirited, will be interesting how I do on a long highway run.

[Matticus91]

Every time I see this topic come up I wonder how heavy footed you guys are lol. I can average 29-30mpg on my monthly trips to/fro NJ/DC. Then again my car is also a 6MT and I find it much easier to baby the throttle than an auto/DCT car.

Also should add I notice a consistent +1-2MPG net increase with JB4 in Map 5 over the stock tune.

[Tenspeed]

I have gotten 30.5 and 31 (with the top down) on two different trips of 160 miles each way. I ran 75 to 80 miles per hour each time. The first trip was right after I got the car just to see if 25 was all I could get. I was pleasantly surprised.

When my wife and I go into the mountains on windy roads we have averaged 27.5 mpg on a 160 mile trip. This even includes a little "spirited driving" (the wife won't allow too much) in the turns during the trip.

Around town it is a different story though. I do well to average 20-21.

[smrtypants44]

Originally Posted by bagekko

I've had mine 2 weeks and am surprised how I am on the low end of the spectrum. Averaging 18ish on mixed driving, but I am always in Sport & DCT Sport or Manual. Its still better than my M5 where I average 14mpg, but no where near the 23mpg I got in the Z3. I am always a big gas consumer as I drive spirited, will be interesting how I do on a long highway run.

Yeah I usually get 18-20

[c1pher]

Just for more insight, I was not in sport mode or sport/manual transmission mode and used cruise the whole way.

I am still getting used to the difference between sport transmission mode and sport mode (button). Also kind of weird to me is if I go to sport trasmission mode and then shift a gear, it stays in manual mode until I go back to regular drive.

[zx10guy]

Originally Posted by Matticus91

Every time I see this topic come up I wonder how heavy footed you guys are lol. I can average 29-30mpg on my monthly trips to/fro NJ/DC. Then again my car is also a 6MT and I find it much easier to baby the throttle than an auto/DCT car.

Also should add I notice a consistent +1-2MPG net increase with JB4 in Map 5 over the stock tune.

Per BMW's own fuel economy numbers, the 6MTs were rated higher than the DCT. The DCTs have an official 25MPG number and the 6MTs have an official 28MPG number. I always found this odd as the DCT has 7 gears versus the manual's 6. You would think they could set up the gearing to have at least one overdrive gear. My understanding is the 7th gear is a 1:1.

[c1pher]

I wondered the same thing as to why the fuel economy would be lower when there was an extra gear. I figured they might be much more aggressive gear ratios and seventh was less of a cruising gear than a pulling gear.

[zx10guy]

Originally Posted by MGM135is

I wondered the same thing as to why the fuel economy would be lower when there was an extra gear. I figured they might be much more aggressive gear ratios and seventh was less of a cruising gear than a pulling gear.

My opinion is that most people who purchase cars with the DCT are going to use it on the street and it'll never see any track time. What they should have done is optimized the gearing for gears 1 through 6 maybe even 1 through 5, and did an overdrive gear for 7 or 6 and 7.