2015 640i mpg

Hi all

As you probably know I have a 640i gran coupe which I understand has the n55 engine

I commute to work each day approximately 7-10 miles each way with a mixture of dual carriageway and town driving with traffic.

start/stop is switched off on it

I get around 21mpg according to the trip computer.

Is this normal or should I be getting much more?

Thanks as always

Jon

 

Hi. I would suspect that is a relatively accurate expectation for the car/engine/journey scenario. Maybe do a brim to brim manual calculation to check, although I suspect it would be lower than 21mpg if this is the reading from the car.

 

7-10 miles the engine is probably only just getting warmed up when you finish the journey. Add on to that some town driving and i would suggest its about right.

I took out a 540i x drive demo the other week and the trip computer was saying 19mpg when i got in it.

I reset the computer and did about 30 miles in it mainly motorway / dual carriageway and it was showing 31mpg.

Why not reset yours and take it for a decent run on motorway / dual carriageway and see what it says then

 

The only 640i GC I have driven showed a long term average of around 23mpg on the OBC when I checked it on a test drive although I obviously have no idea of how the previous owner drove it. Your drive to work sounds similar to mine and for what it worth in the winter I see circa 33mpg in my 640d GC or nearer 40mpg in summer. My OBC shows an average of 40mpg over my 18 month 15K mile ownership. I would hope now its getting warmer your mpg should improve a bit and as others have said a longer run would be a better check. My old N53 engined E61 530i averaged around 26 mpg over my entire ownership for similar driving profile.

 

It is the short runs from cold and in traffic, which really knocks mpg. It is trips beyond 10 miles where the mpg starts climbing to sensible figures. Running the same engine in my F11, it takes around 15 miles in easy conditions for mine to get to about 30mpg.

As suggested, a reset and a decent run (30 miles or more) will give you the best idea if something is wrong.

BTW, when I picked up my F11 at 5,904 miles, OBC for that mileage was reading 22.2mpg. That was use by a BMW UK Director around HQ. My long term average is around 30mpg.

Peter

 

Thanks to everyone that has commented. I had a Mercedes e class coupe diesel before this so am not used to the lower mpg I’m getting with this one. I used to get around 38 mpg so as you can appreciate it’s a massive drop !

I live in London which has the ULEZ charge applicable to where I commute so although the Mercedes Benz was compliant, there’s been a lot more discussion on diesels being pushed out , hence the switch to petrol

 

My 440i (B58 engine) is averaging 37.5mpg over the past 18 months. Lots of longer runs with the engine up to temp etc. As well as some spirited runs….

 

Pls remember it's not uncommon for the OBC to read up to 8% high

 

5M long, 1800kg and 3.0 turbo engine, I'd say this mpg sounds about right on short trips - would expect better on long runs but think it'll be a struggle to get much over 30 mpg....

 

Here's an example of my similar weight touring. Mixed use including a trip to Wiltshire, most in light conditions, without heavy traffic. Corrected (brimmed tests) will be very close to 30mpg.



Peter

 

You can adjust it via the hidden menu, I've done this on my last 2 F10s and the G30. Just press and hold the trip reset button until the menu appears, then use the sum of the last 5 digits of the VIN as the unlock code. The "Correction Factor" default setting is 1000. If the OBC is optimistic on mpg, then increase the number to >1000. So for example, if it is 8% higher than the brim-to-brim mpg, set it to 1080. I can usually get the OBC to read within 1 - 2% of reality this way. More here: