BMW 6 Series - MPG

[mgp20jam]

Difficulty in achieving recommended miles per gallon for 645ci with a light right foot. Computer reads 18.9mpg normally and the best I've had is 24.2mpg on a long motorway run. 47k miles, 2005 model. I was told by owners that they get up to 27mpg average. Bought car before fuel went soaring in price. Has anyone converted to LPG, with what results? It might be cost effective over the next 4.5yrs of ownership. My TVR Griffith 4.3 is more economical with a heavy right foot!

[Major Fallout]

I can get 32mpg on a good run. But I have a different engine, so that's not much use to you sorry.

I can get it down to 8-10mpg if I try :-)

[icepop]

Looking at the figures for that car, it does seem that the mpg is low. But, it's a big lump, and manufacturers do tell porkies, so, unless there is some obvious running problems, you have probably bought, what we called, in the 70's, as a gas guzzler, and the original owner has unloaded it.

[JohnnyRims]

icepop said:

Looking at the figures for that car, it does seem that the mpg is low.

Do they? Official combined figures are 24mpg.

OP it's a relatively heavy car being propelled along by a 330bhp 4.4L V8. Surely you didn't expect much more than high teens?

[Fetchez la vache]

Good lurking btw...

[SubaruSteve]

Similar engine etc to my old B10 Alpina. I would get similar mpg to you, but it is possible to get more by using simple techniques such as not reving over 2000rpm (which was approx 67mph in the B10) and don't use cruise control on the motorway, instead gently slow down as you go up hill and gently accelerate as you go down hill.

Best I got was 34 average from Exeter to Oxford and back. It was painfully slow though!

[trickywoo]

mgp20jam said:

Difficulty in achieving recommended miles per gallon for 645ci with a light right foot.

One post in 49 months? Top lurking

Nearly 19mpg isn't that bad. Look at it next to depreciation and the fuel will be the least of your worries.

[130R]

I have an M6 and get around 17.5 mpg average so I would have thought you would do better than getting an extra 1 mpg, but I would say it is totally dependant on what type of driving you typically do. I do almost no city driving whatsoever, all A and B road.

[832ark]

My best friend tends to get high teens out of his '04 645 so I'd say that what you're getting is about right.

[ronaldo342]

Mine is reading 22.7 just now and thats been a lot of town driving, have had it up to 27 and I dont hang about

[jonah35]

most cars do way less than their stated mpg.

should have seen the fuel rises coming, sorry mate but they are only going to get worse. Mind you £6 to drive 18 miles is a lot

wait till the recent oil price surge filters through and duty is increased in january

a small round trip to the shops will cost you over a tenner - argh.

[derestrictor]

Sounds a tad slurpy; even the Super Spunker M6 exceeds 25 mpg on a c/c regulated 75-80 m-way perambulation.

Clearly, the moment you even look at the naughty pedal, you're f'cked.

[mgp20jam]

Thanks for the hints and when you press the loud pedal the thing just gulps petrol. However, just did a trial on a motorway trip and A road and got the following: 24.5mpg on the computer and 27.5mpg at the same pump when refilling over 350mls. It's definitely the town driving that probably gives me the low 20mpg actual, with a reading of 18mpg..