E92 M3 fuel consumption

[edb49]

In my E92 over 4000 miles I averaged 17.6mpg according to the OBC. This compared to 24.6mpg over 7000 miles in my previous car, a 987 Boxster S.

Lexus IS-F: 24.8mpg
BMW E92 M3: 22.8mpg
Merc C63 AMG: 21.1mpg
Audi RS4: 20.9mpg
Boxster S 987: 26.6mpg

The Merc and Audi have a weight penalty over the BMW/Lexus, which gives them an excuse. The Merc has a slush box, and the RS4 has 4wd drivetrain losses.

But... the Lexus weights a touch more than the bimmer, and it has a slush box. How is it so far ahead of the others with its fuel consumption? They are all relatively close in terms of power outputs and weight!

Edited by edb49 on Sunday 10th February 09:01

[edb49]

Edited to add the fuel consumption of the Boxster S.

So in my own experience of real-world versus combined cycle figures:

Car	Combined Cycle	Real World	% of CC
E92 M3	22.8 mpg	17.6 mpg	77%
987 3.2 S	26.6 mpg	24.6mpg	92%

There's obviously a big discrepancy in how close I got to the combined cycle figures in either car. I am not complaining about the E92 consumption by the way, this is just something that interests me intellectually. Does the M3 engine respond very well to the combined cycle test, or have BMW done a fiddle? Why does the Lexus do so much better?

[Huliganov]

Let the engine run in to around 10,000 miles, everything should be a little loosened up and fuel economy should be better. Plus, check tyre pressures, is your AC on? windows open or closed? how many passengers onboard etc etc etc? They all make significant differences to mpg. I know an E46 M3 can get upto 34mpg on a steady 70mph cruise on the motorway but you have to drive timidly getting there.

[macca]

edb49 said:

have BMW done a fiddle? Why does the Lexus do so much better?

I'm assuming you haven't personally achieved the Lexus or Merc figures quoted, in which case how do you know you wouldn't get 77% of these too?

I got 22.7 on my e46 convertible - average over about 2 years. On the basis that BMW reckon the E92 is something lke 8% more efficient, I'm expecting to do better whith the E92. It'll have to loosen up first tho'.

Edited by macca on Sunday 10th February 15:44

[edb49]

macca said:

edb49 said:

have BMW done a fiddle? Why does the Lexus do so much better?

I'm assuming you haven't personally achieved the Lexus or Merc figures quoted, in which case how do you know you wouldn't get 77% of these too?

I wasn't saying the 77% figure, I was saying the combined cycle one. The Lexus is about 10% better than the BMW.

[macca]

You have queried the bmw figures based on real life experience but don't have the same real experience for the Lexus (unless I missed something). If you did, you might find it only does 17mpg for your style of driving... that's a maybe. That's what I was trying to say when I used the 77% example.

How do you know the Lexus is actually 10% better? If anything, the Lexus figures look cooked considering it has no weight advantage and is a 5L auto.

[edb49]

macca said:

You have queried the bmw figures based on real life experience but don't have the same real experience for the Lexus (unless I missed something). If you did, you might find it only does 17mpg for your style of driving... that's a maybe. That's what I was trying to say when I used the 77% example.

How do you know the Lexus is actually 10% better? If anything, the Lexus figures look cooked considering it has no weight advantage and is a 5L auto.

Sorry, I have not been clear.

I am asking two questions:

1) Why is my real life experience of the M3 so much worse in percentage terms compared to the combined cycle than the same of the Boxster?

2) Why is the Lexus combined cycle so much better than the M3? Despite a larger engine, heavier, and autobox.

[968CSReading]

I think thats good considering the amount of power and its a V8. I get that with the RX8 and its only got 231bhp.

[jonlwright]

edb49 said:

In my E92 over 4000 miles I averaged 17.6mpg according to the OBC. This compared to 24.6mpg over 7000 miles in my previous car, a 987 Boxster S.

/Monty Python mode on/
You lucky, lucky, ba**ard - I dream of getting 17.6mpg.
/Monty Python mode off/

14.2mpg in my M6 from a supposidly 19+ combined!

[Johnbmw6]

edb49 said:

In my E92 over 4000 miles I averaged 17.6mpg according to the OBC. This compared to 24.6mpg over 7000 miles in my previous car, a 987 Boxster S.

Lexus IS-F: 24.8mpg
BMW E92 M3: 22.8mpg
Merc C63 AMG: 21.1mpg
Audi RS4: 20.9mpg
Boxster S 987: 26.6mpg

The Merc and Audi have a weight penalty over the BMW/Lexus, which gives them an excuse. The Merc has a slush box, and the RS4 has 4wd drivetrain losses.

But... the Lexus weights a touch more than the bimmer, and it has a slush box. How is it so far ahead of the others with its fuel consumption? They are all relatively close in terms of power outputs and weight!

Edited by edb49 on Sunday 10th February 09:01

I always got 24MPG out of my RS4 (just sold), when I used the E92 M3, it gave 18MPG!!!, not driving hasrd just running around.

[taffyracer]

I did 900 miles last week and it retuned 23.1mpg, cruise on a steady 82mph all the way, not that bad really for what is probably the best V8 engine currently on sale

[edb49]

taffyracer said:

I did 900 miles last week and it retuned 23.1mpg, cruise on a steady 82mph all the way, not that bad really for what is probably the best V8 engine currently on sale

Best V8 on sale? I beg to differ
http://en.wikipedia.org/wiki/Weineck_Cobra_Limited...