Does fuel economy improve after bedding in period?

[Bob Santorini]

Hi, I have now done about 1500 miles and since the 1200 mile service I've been driving mainly in town with a fee blasts up country roads..
I seem to be returning an average of 16mpg! In the same conditions my 2007 RS4 was returning around 19mpg. That car was heavier, 4wd and 200cc larger in engine capacity and claimed the same power output.
Mmmmm.

So I guess I need folks who purchased their M3s from new to advise if the economy improves with age?

Thanks

Nick

[gblansten]

13.5 here and my fuel economy worsened after the 1200 miles because of more throttle and higher rpms.

[tibra1]

Generally yes..the engine is still breaking in and friction tolerances are tighter hence you tend to experience worst mpg in the break in phases..(assuming same driving style) you should improve mpg after break in

You also tend to consume more oil in the break in phase so dont be alarmed if you need to top it off soon

[TVMA Doc]

Originally Posted by Bob Santorini

Hi, I have now done about 1500 miles and since the 1200 mile service I've been driving mainly in town with a fee blasts up country roads..
I seem to be returning an average of 16mpg! In the same conditions my 2007 RS4 was returning around 19mpg. That car was heavier, 4wd and 200cc larger in engine capacity and claimed the same power output.
Mmmmm.

So I guess I need folks who purchased their M3s from new to advise if the economy improves with age?

Thanks

Nick

You may find that the M3's computer is "conservative" like most things BMW. Mine keeps telling me that I'm averaging 16.8 MPG (nearly 100% city), when I calculate it out to be closer to 17.5 MPG.

There were even a few shifts when I didn't hit the rev limiter thrown in there.

By the way, where did you find a spot to put a bed into your M3? I can't even fit a futon in the back seat of my E90.

[DBH]

Actually this engine doesn't fully break-in 'till around 15k miles. If you drive the same cycle (i.e.: daily commute) at the same speed at 1.5k and 15k, yes you'll find that you've got improved gas mileage. However, most M3 drivers tend to go a little heavier on the gas pedal so mileage tends to go down as you put the miles on.

[M3PO]

Your RS4 had direct injection. That will inherently boost gas mileage, all other things being equal. Also, while it was AWD and had more frictional drivetrain losses because of it, it had narrower tires, thereby reducing friction with the road. When you consider that, and the error in each of the meters, that discrepancy makes sense.

I haven't owned my car since it was new so I can't answer your question but I did get a nice boost in gas mileage when I removed the cats (replaced with HFC).