M40i MPG
- Thread starter benv6
- Start date
I actually checked this on Saturday. Driven almost always for fun, including 12+ forum runs and a forum run to the Pyrenees over 17k an average of 28.0 mpg which I’m most impressed with given how it’s driven 
Scottish Borders
Argyll Andy said:I actually checked this on Saturday. Driven almost always for fun, including 12+ forum runs and a forum run to the Pyrenees over 17k an average of 28.0 mpg which I’m most impressed with given how it’s driven
Mr Andy suffers from ‘plumbus pedites’ syndrome…
Redheadlady
Member
I’m averaging 25/26 mpg commuting but I’m mostly driving outside of peak hours as I do shifts and that’s with the odd sport mode burst.
Well after Andy’s figure I’m completely ashamed by my M40’s lifetime average of 40.7 mpg :lol: Mostly motorway driving at 70 and the odd spirited drive. On one of my journeys from Bristol to East Yorkshire, I managed an amazing 49.9 mpg I’m well impressed by this remarkable engine
I’m well impressed by this remarkable engine I get around 26-28mpg in general mixed driving. On long motorway runs I get 33-34mpg. I almost always fill my car with super-unleaded (98 RON) which will make a small positive difference to the economy. Of course that's completely wiped out financially due to the higher fuel pricebenv6 said:
sars said:
Mine would have to be on the back of a transporter to see those figures
Yes [ref]sars[/ref], you do need to do better, mine is slightly artificially inflated given the use of that blue eco mode to the Chunnel and back last year when it was definitely returning figures closer to your average
[ref]benv6[/ref], mine is possibly not a good indicator to go by as I don’t do commuting in it at all. Scottish countryside and sports mode as soon as I leave the house. Nearest dual carriageway is 70 miles away and always driven in at least sports mode apart from the long boring motorway trip’s mentioned above.
B21 said:Mr Andy suffers from ‘plumbus pedites’ syndrome…
I will not deny nor contest any of that
At the summit of the picturesque fens
IME the B58 engine is a very frugal (for a 3 litre 6 pot turbo petrol) beast on longer journeys at motorway speeds. In town, or short journeys, it's pretty grim, as would be expected of a 3 litre 6 pot turbo petrol.
I got 22mpg around town average and 44mpg motorways in my B58 (a heavier car and slightly more powerful version than the G29).
That was using 100% E10 95 ron 'poor-man's' petrol. I could never justify the additional cost of the "higher octane with added stuff that I have no idea what it does, or doesn't do, and there is no way of proving it, but I use it anyway because it makes me feel like a petrolhead and I must be being really sympathetic to my car although it's costing me a fortune" stuff TBH.
I got 22mpg around town average and 44mpg motorways in my B58 (a heavier car and slightly more powerful version than the G29).
That was using 100% E10 95 ron 'poor-man's' petrol. I could never justify the additional cost of the "higher octane with added stuff that I have no idea what it does, or doesn't do, and there is no way of proving it, but I use it anyway because it makes me feel like a petrolhead and I must be being really sympathetic to my car although it's costing me a fortune" stuff TBH.
DevonPaul said:It must be all that lack of weight due to being a pedal missing
The torque and acceleration more than makes up for that missing pedal :wink:
buzyg said:Wow! those figures are a bit different to the ///MR. Some things certainly have improved.
John, when on our last proper group run, both the Z3M and Z4M were much heavier on juice when we stopped to refuel. This was the case no matter what route or type of driving. The B58 engine is an absolute peach imo
The Z4M offers a more rewarding drive, thanks in part to a manual gearbox and hydraulic steering, it's these two things, IMO, that stop the Z4 M40i from being a great sports car. The engine though, there's no comparison, I'd have the B58 all day and every day, yes there is something about a normally aspirated I6, the purity of it. However, that S54 shows exactly how restrictive that torque gain is over cost. The B58 is just superior, well at least 135 Nm more superior
benv6 said:
Mine gets 28.8 miles per USA gallon. That's about 35 miles per UK gallon. I've never reset the trip-o-meter. I always drive in the "sport" mode, and have never taken a trip over about 2 hours. Mostly country, winding road trips, very little interstate driving. My car only has about 14k miles.
Doug