[LaCross]

Quick question for those who are more knowledgeable than myself.

I hear driving normally, people get around 22 mpg with a mix of city and highway.

However I am having a very hard time keeping even a 20mpg avg while I am babying it as much as I can. Are there any common issues that lead to poor fuel economy?

I did have a stored P2A17 code in my DME. I havent checked if it came back or not.

[GetSomeE92]

What kind of fuel are you running?

I get between 11 and 14 mpg with mostly city driving, but I am running around an E50 blend. If I do a lot of highway miles, the mpg increases, but I don't drive on the highway as much as I used to. I've found that running E85 blended with 93 has resulted in significantly worse miles per gallon, but much more smiles per gallon.

[335NJ]

Originally Posted by LaCross

Quick question for those who are more knowledgeable than myself.

I hear driving normally, people get around 22 mpg with a mix of city and highway.

However I am having a very hard time keeping even a 20mpg avg while I am babying it as much as I can. Are there any common issues that lead to poor fuel economy?

I did have a stored P2A17 code in my DME. I havent checked if it came back or not.

A carbon cleaning wouldn't hurt depending when it was done last, if ever. I've seen people gain 3-4mpg alone with that. Dump a bottle of Techron into the tank too, and make sure you're using good fuel, not Wawa or cheapo gas, 93 octane is best, but 91 at minimum.

[Jeff@TopGearSolutions]

I averaged 22 MPG for years in my 335i that was mix of mostly spirited driving, cit and highway. On a bad week I'd average 19 with heavily spirited driving.
Best way to save gas is watch your boost and stay out of it during acceleration and throttle transitions.

If that code keeps coming back it may be the cause of your mpg but typically driving habits account for a 35% increase or decrease in MPG.

E85 uses about 22% more gas then 91-93 octane.

[LaCross]

19 with heavily spirited driving would be great. I struggle to get 20...

I use sunoco or BP 93 oct only. I dont think a carbon cleaning has ever been done

[angel_rod]

I get 19 on average :/

[LaCross]

With the way I baby it there must be something stopping my MPGs... perhaps the carbon cleaning could help

[Jeff@TopGearSolutions]

Originally Posted by LaCross

19 with heavily spirited driving would be great. I struggle to get 20...

I use sunoco or BP 93 oct only. I dont think a carbon cleaning has ever been done

I think the difference is when I drive spirited its literally a short burst in 1 trip so the remainder of the trip I drive like a grandma. My buddy used to get 23-24 MPG in his 135i but he did mostly highway.

Carbon cleaning should help anyone with over 35,000 miles but like I said before, that MPG can really sway a lot on your driving habits, throttle transient between gear changes and overall how much you stay out of boost.

As soon as you enter 1-3 psi of boost you use significantly more fuel then if you stayed in vacuum.

Those of you who know tuning and knowing fueling know how much more fuel is required for boost fuel tables VS vacuum fuel tables of the same power.

There was a time when I had an aftermarket A pillar boost gauge on my car before all the gauge hi-jacking and stuff and I'd literally accelerate just enough to stay out of boost, which would maximize MPG by no accident.

[Myrder]

around 18-19mpg mixing E45-50 mixed driving. I can get that quite lower if I push the GO pedal more.

[jimmer411]

19mpg all city driving.

[Miko226]

Originally Posted by GetSomeE92

What kind of fuel are you running?

I've found that running E85 blended with 93 has resulted in significantly worse miles per gallon, but much more smiles per gallon.

Agreed could not have said it any better

18-20 mpg on only 93 with 95% city driving. Much worse on e85 tanks but thats mainly because im always on it with e85 however there is significant mpg loss with e85 blends

[charrigan]

I'm a bit more highway that most. I see 25-27mpg using 93 and 22-25mpg with e30.

[RIDERDIE]

Damn i feel lucky. Don't drive crazy but I do enjoy the throttle on the clovers. 60% hwy 40% city a good amount of mods and I'm at 29 mpg's. 42k miles on my 07. No carbon cleaning and original plugs.

[LaCross]

How u do dis

[iturbo_bmw]

~e50+ i get 12-14 mpg
~e20-e40 - 14-16 mpg
91 pump flash ~17ish
stock flash ~18ish

city driving in the bay during traffic hours

[LaCross]

My commute to work is a traffic lighted highway. Basically .5-2 miles, stop, .5-2 miles, stop, ect

But I think a 20 avg is low. And that 20 avg is after a 70 mile highway trip. Before that my avg was 18.9

[Spandexder]

I'm averaging 17 around town but can get as high as 34 on the highway (a steady 65-67 mph). However, I run my tires 7 psi lower than the max tire pressure. The ride was a little bumpy on run flats but once they were swapped out the ride is tolerable.

[AW M4]

Avg between 18-23 mixed city and highway

[Ingeniator]

Get about 22-24mpg on avg. mix city highway but it's mostly a 50mile commute to work each way. I avg 650-700km a tank.

[TotalBlackout]

I was getting about 21 mpg mixed hwy/city. I got new tires and alignment, now I'm getting 24-27mpg. Alignment was terrible.

Still need carbon cleaning. I'm at 75k miles. Tuned everyday.

[MTTH]

You guys are all lucky! I get 14-15 MPG BABYING the shit out of my 328

[ferocity02]

I'm averaging 24-26mpg with 40/60 city/highway. My average speed is usually 40-45mph.