Fuel economy in the E90

[fatass]

damn, thats terrible. i'm at 24-28 with my 335i. not just the money but the pain in the ass constantly filling up. maybe m4 isnt such a bad idea

[mdosu]

Originally Posted by MineralWeiss

I too heard all the horror stories relating to fuel economy, but I recently drove my E92 from OKC to Traverse City, MI, then on to Ann Arbor to watch the UM/ND game and back to OKC and averaged 23.4 MPG...very pleasantly surprised! That's what we averaged in my wife's obnoxiously slow Nissan Juke when we took that on a trip.

don't forget to note that the Juke is also obnoxiously ugly.

[Sinister Crayon]

Originally Posted by fatass

damn, thats terrible. i'm at 24-28 with my 335i. not just the money but the pain in the ass constantly filling up. maybe m4 isnt such a bad idea

I'm not filling mine up any more often than I did my 135i... but that got about 22mpg and had a smaller tank than the 3 series. Honestly, I am actually filling my M3 less often, which was actually a rather nice surprise for me. Of course, I also don't immediately fill it when the light comes on...

I think if gas mileage is a concern, the M3 and even the upcoming M3/M4 is probably not the car for you. I doubt you're going to see 24-28mpg even on the F8x. It will be better enough not to get slapped with the gas guzzler tax, but I wouldn't expect much more out of it than that. Presuming the new engine is of the N54/N55 lineage, it's a great engine but is not going to sip gasoline. Hell, even the might N20 4-banger is a good engine but isn't exactly what I'd call frugal even compared to my girlfriend's A4. I drove an F30 328i for a week recently so we had a great point of comparison (both auto).

[Billj747]

Originally Posted by Sinister Crayon

I am also of the opinion that it is possible to get better gas mileage with the 6MT than the DCT... a theory that was borne out at least with a pair of 135i's... I got better gas mileage with the 6MT than the DCT, though only by about 5-10%... not markedly better. The M3 is almost certainly the same.

Interesting. I would have thought the DTC transmission would get better mileage because in automatic mode it can get into 7th gear by 40 mph and most people wouldn't be doing that in a manual.


Its a bit ridiculous that my 5.0L pushrod 2-valve supercharged fox body Mustang gets better mileage than my S65

[Sinister Crayon]

Originally Posted by Billj747

Interesting. I would have thought the DTC transmission would get better mileage because in automatic mode it can get into 7th gear by 40 mph and most people wouldn't be doing that in a manual.

You'd think so if all else were equal... but the final drive ratio is different as well as the gear ratios. As I recall, the M3 6MT final drive is 3.84 with a 6th gear ratio of 0.85... equals 3.38 to the pavement. The DCT is 3.15 with a 7th gear ratio of 1.00 (direct drive)... so 3.15. That means the 6MT runs about 7% lower RPM at highway speeds.

The close ratio gears on the DCT are why it's faster accelerating and better generally for track use. I know... probably start a flame war there... but there's no doubt in my mind the DCT is the better transmission for track use. Also if you spend a LOT of time in traffic. But if you live in an area of the country that has some lovely sweeping roads and not horrible traffic, the 6MT is definitely the one to have. For my needs the 6MT is best... for others it's the DCT.

[Billj747]

Originally Posted by Sinister Crayon

You'd think so if all else were equal... but the final drive ratio is different as well as the gear ratios. As I recall, the M3 6MT final drive is 3.84 with a 6th gear ratio of 0.85... equals 3.38 to the pavement. The DCT is 3.15 with a 7th gear ratio of 1.00 (direct drive)... so 3.15. That means the 6MT runs about 7% lower RPM at highway speeds.

The close ratio gears on the DCT are why it's faster accelerating and better generally for track use. I know... probably start a flame war there... but there's no doubt in my mind the DCT is the better transmission for track use. Also if you spend a LOT of time in traffic. But if you live in an area of the country that has some lovely sweeping roads and not horrible traffic, the 6MT is definitely the one to have. For my needs the 6MT is best... for others it's the DCT.

Lower final drive = lower RPM

The DTC should have a lower rpm in top gear than 6MT.

Lower RPM generally = better fuel economy, which is why I said the DTC keeps the rpm very low during casual DD than most people in a 6MT who usually don't shift at 3k RPM.

[Sinister Crayon]

Originally Posted by Billj747

Lower final drive = lower RPM

The DTC should have a lower rpm in top gear than 6MT.

Lower RPM generally = better fuel economy, which is why I said the DTC keeps the rpm very low during casual DD than most people in a 6MT who usually don't shift at 3k RPM.

Yup... you're right. Had it completely upside down. This is what happens when I type without coffee; brain fails to engage first.

Honestly then, I have no idea why I consistently get better fuel mileage switching between DCT and 6MT LOL

[radiantm3]

Originally Posted by Sinister Crayon

I'm not filling mine up any more often than I did my 135i... but that got about 22mpg and had a smaller tank than the 3 series. Honestly, I am actually filling my M3 less often, which was actually a rather nice surprise for me. Of course, I also don't immediately fill it when the light comes on...

I think if gas mileage is a concern, the M3 and even the upcoming M3/M4 is probably not the car for you. I doubt you're going to see 24-28mpg even on the F8x. It will be better enough not to get slapped with the gas guzzler tax, but I wouldn't expect much more out of it than that. Presuming the new engine is of the N54/N55 lineage, it's a great engine but is not going to sip gasoline. Hell, even the might N20 4-banger is a good engine but isn't exactly what I'd call frugal even compared to my girlfriend's A4. I drove an F30 328i for a week recently so we had a great point of comparison (both auto).

I went from an 18mpg average in my 135i to 15 in the M3 (mostly city). Not too bad.

[DrakeKemper]

Before the supercharger I was getting 240 miles per tank in the city, and now I get 200.

Before the supercharger I was getting 322 miles per tank on the highways, and now I get 280.

Not too bad to be honest, WAY more fun lol.

[FogCityM3]

15.9 mpg including about 20% of very spirited driving.

[Techjunkie666]

I get 16mpg which is 1 mpg more after getting benvo stage II tune, DCT and servtronic tune.

[mdosu]

Originally Posted by DrakeKemper

Before the supercharger I was getting 240 miles per tank in the city, and now I get 200.

Before the supercharger I was getting 322 miles per tank on the highways, and now I get 280.

Not too bad to be honest, WAY more fun lol.

those figures are also similar to number of free lap dances received when you pull up in an M3

[Billj747]

Originally Posted by Sinister Crayon

Yup... you're right. Had it completely upside down. This is what happens when I type without coffee; brain fails to engage first.

Honestly then, I have no idea why I consistently get better fuel mileage switching between DCT and 6MT LOL

Beats me, even more so how my ancient 23yr old Mustang gets better mileage

People should post DTC or 6MT to their mileage posts (not to start a war, just to know more when reading posts).

[gan1hck]

[jbeene]

I've had a few 4.8' s and 3 E90 M3's. The mileage is similar but the M3's tank is smaller so you are filling it up more often. I get around 400km out of a tank in the city in the M. In the 4.8 I was getting about 460 km due to the larger tank.

At the track in the M I got 199 km's out of a tank. Of course I was going 235 kmh on the front straight

[sviswan]

Got my best mpg rating this week. 95% highway driving. 356 miles on a tank, and it took 17.26 (i really got into the reserves) gallons to fill up, therefore i got 20.625 MPG.

[Patrón]

Just drove 600 miles , got 21/ gal driving between 75-90. Unfortunately it didn't include any aggressive passing etc... Great drive. I loved it.

[Btturbo]

Originally Posted by Transfer

Average 14-15 mostly city driving, short commute. With true highway driving 20-21 is probable, at least with DCT.

Exactly what I average.....when I even care to check!

[Btturbo]

Originally Posted by gan1hck

AWESOME!!! I saw a video review the other day, is it true we are speed limited to 150mph? That would suck on some tracks.....

[mdosu]

Originally Posted by Btturbo

AWESOME!!! I saw a video review the other day, is it true we are speed limited to 150mph? That would suck on some tracks.....

155 indicated, but true (measured) speed is about 150.... with limiter removed, top speed should be around 165-170ish. Most amateur tracks in the US, you probably won't hit anything north of 120, and it'll be very brief.

Road and Track article: they did an ultimate sports car comparison, where they took the M3 and other cars on different tracks and courses, one of them was an oval. The M3 didn't get close to the top speed on an oval.

http://www.roadandtrack.com/car-revi...ate-track-test

[Billj747]

Just went through a whole tank on a road trip. DTC, pure hwy driving at 80mph and not accelerating too hard. 21.14mpg calculated.

[M.Hagen]

When I purchased the car I drove it from Minneapolis to Salt Lake. 2 days of 99% highway driving and averaged 22.5 mpg for the 1280 miles I logged. I was pleasantly surprised as I was budgeting for 18 mpg.

My daily commute is on 35-45 MPH roads with nearly no elevation change for 8 miles. With my first full tank since my purchase, which included a full Saturday of canyon driving and jackassery, I averaged 21.3 mpg.

This is all based on the info screen, not calculated from the pump.

... [puts on flame suit] I drove a Honda Insight for 4 years [/flame suit], and learned to anticipate signal changes and to engine brake to a stop to limit unnecessary deceleration and acceleration. I've got the light timing fairly well understood on my daily route, so I use that practice to my advantage on the M3, which may contribute to my 'unusually good' first tank. We'll see how long the trend continues....