Gas Mileage M45

[Mdeniz]

I know this has been discussed but my god this car gets the worst gas mileage of anything I've ever owned that includes a Hemi 1500 5.7L, and several 700hp++ cars. I am averaging between 14-16mpg no matter how i drive the car and I find it ridiculous, has anyone found any specific mods that help this a bit...maybe the uprev tunes? /rant

[yosM45]

Easily....with normal easy driving, I get 18. That requires work. On average I get 17.

I've never gotten less than 21 on the highway on cruise, and 23 at my best 65 mph on cruise.

[bejjutsu]

that seems low by about 4-6mpg. Maybe time to have it checked out? Do you get these results from driving the speed limit and smooth acceleration?

[Mdeniz]

yes, that's why i'm posting because I know the EPA estimates are BS most of the time, but not by this much...the car runs absolutely beautiful no hiccups, misfires, flat spots or anything else...

[mexillis]

is that strictly city driving? I average 19-20 with mixed, 35-45mph city and 65-70mph on the highway. When my low fuel light goes on I usually am at 300 miles driven.

[Mdeniz]

I'm all city driving :/ so it is probably all about the same then. I know you have more mods than the average guy, did you notice a drastic difference for the better or worse with any of your mods?

[hahakenny]

I get about 16mpg average on mine. But on occassion, I can't help but want to feel the power of the engine so I tend to be a little heavy footed.

[atlM35]

This is why I'm thinking about getting an M45. My 35 gets an average in the mid 17's mixed (and that's me taking it easy on the throttle.)
I have yet to get 300 miles out of a tank on mixed driving.
The same numbers on my previous M35 as well.
50 more hp with roughly the same fuel mileage, no brainer. The wife can drive the 35

[Iconic]

I have a m45x and I get 17mpg on 80hwy/20cty.
A 12 cylinder mercedes gets a better milage.

[Mdeniz]

I have a m45x and I get 17mpg on 80hwy/20cty.
A 12 cylinder mercedes gets a better milage.

yeah its pretty ridiculous, i'm gonna have to get a daily driver for my daily driver lol

[bejjutsu]

the only mod to improve your city MPG on an M45 is to swap the engine for a V6, and even then, it won't be that much better... Just gotta get used to spending a few hundred more on gas than the average driver per year (I get 14-17MPG in downtown city driving)

[About Tree Fiddy]

I'm actually getting about 2 mpg better fuel economy on my new 2012 550i than I got on my M35S even thought the EPA sticker is lower. It's pretty insane that a car that has almost 100 more hp, 188 lb-ft more torque and outweighs it by about 500 lbs. wins the fuel economy battle.

[mexillis]

I'm all city driving :/ so it is probably all about the same then. I know you have more mods than the average guy, did you notice a drastic difference for the better or worse with any of your mods?

I only have two performance mods, exhaust and tune. When I got the exhaust installed I noticed a slight improvement then up a little more with the tune but nothing can help in city driving besides driving in manual mode imo. It will let you stay in 3rd gear until you come to a complete stop unlike in auto where it downshifts to 2nd and first. I don't mean keep it in 3rd either. As for the v6 motor swap, for the 06/07 M35's it was like a 1mpg difference compared to the V8 which is why I bought the 45.