[1 AKY]

without wanting to state the obvious, have you tried working out your MPG by filling a few tankfuls and seeing how many miles you get, rather than just relying on the OBC which may be playing tricks?

[Budgie]

I could understand if it was low mileage and not performing as many dont limber up till really run in nicely.Might just be ya driving style.

Carlos has a 335d Remapped and gets real low others remapped 335d get higher...horses for courses.

Think about how you ask the car to drive and your style im sure theres a clue in there somewhere.

I know im a pure motorway and A road driver so i see constant high numbers,so anything urban is never gonna show on my OBC.

[boxtaboy]

I assume the car has been into a BMW Stealers and they've run the usual diganostics and come up with a blank. They seem to be too reliant on "computer says no" rather than using some good old grey matter. I've heard of a number of instances where the standard checks some back fine but once the MAF is replaced / cleaned, the car is miraculously cured.

[user12134]

is there a way to generate MAF error so that it is flagged by BMW diagnostics and then replaced under warranty..

[gIzzE]

Originally Posted by paulcurtis

I would say those figures were bad. Certainly the 120d, mine was 43 average with a lot of that around town and 50+ on a long run.

I wonder how much of this is driving style vs actual different tolerances in the engines. Perhaps we're all worrying about nothing but then a 20% saving in fuel costs does add up these days.

cheers
paul

Was yours an auto??

I would saying driving style and where you drive can effect consumption by as much as 40%.

[Budgie]

Originally Posted by gIzzE

Was yours an auto??

I would saying driving style and where you drive can effect consumption by as much as 40%.

Yeah im in total agreement here gizze

[MEGA]

No matter HOW I drive I can't get it above 33-34 on the commute to work. The commute is 15miles, 9m of traffic 6m of decent dual carriageway with roundabouts..

On a more spirited run in thismorning, the resultant figure was 24.

[CraigUK]

I've noticed that my economy is alot worse when the engine is cold. I'm sure that's true of all engines both petrol and diesel however it seems to take some time to warm through and become economical. At 15 miles each trip your engine will be below operating temperature for alot of that. Remember it's not just the water but also the engine and transmssion oil. Just a thought.

[MEGA]

Living in London as I do, that 15m takes over an hour. So you have a point, but its not so relevant I don't think compared to being up your way.

[Budgie]

Free wheel it down roxeth hill and itll do a constant 99.9mpg

[gIzzE]

My 320d used to take 8 miles or 15 minutes to get to temp.

[paulcurtis]

I can't talk for others but i compare a 120d with 320d, same area, same driving and same style and the 320d is around 20% worse. The only other difference being the cold weather (and the fact that the 320 is heavier) but it's not *that* much colder than normal (around here anyway).

The 320 is older and higher milage, so the MAF conversations could have something to do with it. Im unsure how i'd go about finding whether this is a cause without taking it to a garage.

It's not the end of the world, but if i can get better milage that would be great, 20% over the course of a year can make a fairly big difference. Well it could pay for a new MAF for sure...

And gizze, it was a manual 120d so as you say can't really draw comparisons to an auto which i've never had or driven!

cheers
paul

[gIzzE]

I got 39mpg from my 320d ED auto with non run flat 19" wheels on, I got 44mpg from the same car with the 17" m-sport wheels and the ED tyres. So over 10% difference between different wheels and tyres.

The loan 320d manual, again an ED car returned 48mpg doing the same trips, however, the load pre ED 320d se touring manual I had when I had the 120d returned only 34mpg.
I forgot I had that car for a couple of days, it was in Jewish Racing gold with a yellow interior so probably wiped it from my mind!!

Our little 120d auto used to drop down to 26.9mpg round town, but then I guess the petrol equivilent would be down as low as low as 20mpg. Hmm, probably not actually as my 3.2 Quattro estate with a tiptronic box never gets lower than 22mpg even in winter round town.
Difference is the A6 will also never see more than 34mpg on a run where as the diesel can see 40+.
Although, 34mpg at 86p is probably about the same as 40mpg at 99p??

[330dan]

my e46 330d gets 24mpg and thats driving it like a vicar

[Budgie]

Originally Posted by 330dan

my e46 330d gets 24mpg and thats driving it like a vicar

Bet thats cos you have a auto...manual in a e46 mpg wise is massive difference.

I had a remapped 260/265 bhp manual 330cd (stock 204bhp)way back and it used to be fine and well efficent.Mate had a remapped auto and it was shockingly the other way.

[jinjur]

Didn't get the RR done guys

Have been having dizzy turns and feints while driving or standing so have been unable to commit any time to it as of yet....

Maybe next week some time if this would just go away

Jinj

[zltm089]

I've just checked my on boad computer....it says 17MPG....is that right?

[user12134]

I am not sure if my E90 320d (non ED) has a problem or not. The stealership has checked the car again and have said that the car is absolutely fine.
Yesterday I went from London to Birmingham (and back) and the fuel economy was topnotch. I was over 50mpg for the whole time even when driving at 90 and 100 mph. The average consumption I got for the return trip was 48.
The only thing I am concerned about is that when driving in the city, I couldn't get more than 32-34 mpg.
My other observation is that my car is'nt very fuel efficient when idling. The consumption goes down very quickly when waiting at traffic signals or stuck in traffic.

[F104]

Jinjur, as a last thought is your engine using oil? If it is, and if you have a closed crank breather system your intercooler might have quite some oil in it. That would increases the pressure drop, and increase intake temps withouth flagging fault codes, and be no good for fuel economy

[gIzzE]

Originally Posted by user12134

The only thing I am concerned about is that when driving in the city, I couldn't get more than 32-34 mpg.

Diesels are crap in city driving.

Originally Posted by user12134

My other observation is that my car is'nt very fuel efficient when idling. The consumption goes down very quickly when waiting at traffic signals or stuck in traffic.

What do you expect, you're doing 0 mpg.

[user12134]

Originally Posted by gIzzE

Diesels are crap in city driving.



What do you expect, you're doing 0 mpg.

What I meant was as compared to other cars, it looks as if the consumption at idle is higher than normal.

[grey man]

Just done today about 300 miles (Cambridge and back) via motorways (M6, A14 etc) and keeping well up to the speed limits on roads with lots of cameras and middle/fast lanes elsewhere ........ 44 mpg (BP Ultradiesel or whatever its called)- which from a 335d (auto) is a figure with which I'm very content.