My 640D poor mpg?

[Dogmatic6]

Hi all,

I've had my 640D GC for a few months now and the most I've managed on longish motorway run is around 40mpg. Does that sound right?

The car is just under 3yrs old with 16k miles on it when I bought it. It lived in London so not sure if it spent it's life doing short journeys or not.

Cheers

[Jon D]

Are you doing brim to brim checks or relying on the trip computer?
The former gives you an actual figure. I find my OBC quite accurate but I've heard reports of them varying. You can check the accuracy of yours by resetting the journey computer every time you fill up.
40 mpg for a diesel on a motorway trip sounds low - did you reset the trip and long-term computers when you bought the car?

[NINJA59]

Do proper brim to brim as said above.

You can actually alter the "correction value" for the MPG OBC fairly easily.

Overall it does sound low, but it does depend on how much you are using that right foot.

[6coupe]

Depends on the motorway and the speed, cruise used etc. If you're happy to sit at 70mph on cruise (without constant up/down due to traffic) I'd expect nearer or above 50mpg, but mine is remapped so that adds a little anyway.

[Dandanbmw]

My 640d is remapped which does help a little when plodding or doesn't help when you have a heavy foot.
My worst tank since owning is 23mpg and my best is 48.8mpg but I have had it up near the 60mpg on some long journeys but I haven't been able to plod and the mpg goes out the window a little.

My daily drive to work is 7 miles there and 7 miles back so hence my mpg is never going to be great and I have a heavy right foot too. But for the power it has I'm more than happy with the fuel economy.

[Bored of Audi]

On a run from Sheffield to Ashford (every two weeks) at 70-85mph (oops I am lying) I get around 52mpg and on the way back around 49mpg....

[Dogmatic6]

Hi All,

Thanks for the responses

I will need to do a brim to brim check as I'm relying on the trip computer which resets after every trip. The long term trip computer is averaging 34mpg.

I do tend to sit between 70 or 80 on a 25 minute motor way journey although most of my journeys are maybe around 15 mile trips.

I think the last full tank I got just over 500 miles out of it.....maybe.

Cheers

[Dogmatic6]

Also, I had a BMW Z4M before the 640D lol and I was getting 21mpg on a good day with that!

Both cars are amazing and 40mpg is good for the power available. Just want to make sure nothing is wrong with mines.

Cheers

[BMWLad]

I normally get about 450-475 to a tank. Relatively short commute plus a willingness to use 100% throttle mean that I'm never going to get close the quoted figures.

[Dogmatic6]

Originally Posted by BMWLad

I normally get about 450-475 to a tank. Relatively short commute plus a willingness to use 100% throttle mean that I'm never going to get close the quoted figures.

Yeah I think this is my problem lol coming from the Z4M means I've still got a heavy touch on the throttle. Will see how it goes.

Cheers