MPG ... 318i

[Matty-H]

Can i ask what sort of mpg people are getting in thier 318i's

Mine is being totally usless and impractical on fuel. 16.53 Miles to the gallon is utter toss... I dont drive the thing like a nutcase either!

Its done 140 miles on 40 quid of fuel... From filling it up from the light just coming on, and back down to the light.

Surely this cant be right, even on a decent journey its doing crap!

Anyone?

[JSAMacLean]

Yep, that's really bad. If it is over-fuelling that bad you should smell it or feel some seriously lumpy driveability. Also it'll be contaminating your oil something chronic.

What does the swing-o-meter show when you're driving? Mine pretty much consistently shows around 30mpg unless I'm doing hard accel, and I never get less than 300mi per tank. Recently I shot a can of that 10K PowerBoost de-coke stuff from Halfrauds through. Worked a treat improving driveability and fuel economy is up by about 10%. Now I'm consistantly getting >35mpg. Last tank was 380mi light-to-light.

[jmc330i]

Fuel leak?

[Matty-H]

When im driving it i keep the econo meter very close to 30mpg if not above sometimes. I'll boot it the odd time but not often enough to make a big difference.

It does smell a bit rich sometimes tbh. But i cant find any signs of a fuel leak. It is sometimes lumpy too. Do these engines work off a tempiture sender to the ecu to adjust fueling ect? I know early digifant systems on golfs and stuff do or are beemers totally different?

Cant think of anything else it could be. Ive ran it really low and put super unleaded sometimes and it semt to make a bit of a difference. The fuel filter is recently new and ive changed the plugs and allsorts.

[E30Mark]

I used to get 380 / 400miles from a tank in mine.

Double check there are no fuel leaks from the hoses that run between the inlet manifold.

[bobcat]

my 318i baur regularly gets 550-580km to a tank/100m=160k so around 350m a tank.

[sihooker]

I get 32 -35mpg from my M40 1.8,depending on how i drive,etc.

You must have a fuel leak,cos i'm sure it just wouldn't run right with a mixture as strong as your mpg would suggest...maybe your tank has split/rusted?

[Matty-H]

There isnt any signs of a fuel leak. im going to put it on the ramp and double check today. Its really annoying me now. I put £30 in it last night from the light so thats half a tank it read. Ive done 20 miles and its used a quarter of a tank. Ive only been from the petrol station, to town, work and back

[jmc330i]

The guages arent always accurate, like 1/4 for 1/4.

Mine takes ages to come down from full, but then suddenly drops from 3/4 to around a 1/4 in about 50 miles, and then it does 150+ miles before its drops below empty and another 50 odd before the light comes on.

Using the fuel guage isnt an accurate way of telling how much fuel youve used. You need to brim the tank and drive a minimum of 100 miles (although the more miles the better to get a more accurate figure), then re-brim the tank and work it out from that. Then you will know what MPG you are getting and if you have a problem.

[Dezzy]

I have just got 382 miles from light to light in my new chromie. That includes motorway and round town. Even a little thrash. Just for sh1ts and giggles. That's ruffly 38 mpg. My bet would be rotten filler neck.

[chris318i]

After replacing all fuel lines on my 1.8 M40 i get 30mpg pretty much all the time, although mine is an Auto.

[asmith88]

my is is a bit wonky, i always got around the 30 mark, put a new chip in and was getting maybe 36-38mpg

however apparently its mapped for 98 ron, tried that and im only getting 32-33

[XRMike]

Im experiancing similar problems with my 318i. Im dissapointed with the mpg return tbh, the engine is unrefined, idles poorley, missfires and the temprature is all over the place. So, im going to rip out the m40 and drop in an m50 instead, then the low mpg figures will be more worth while, i'll have a refined engine which will be silky smooth and have some power

[Dezzy]

M50 is a good choice. You will get decient mpg as well. The m40 in my chromie is mint 76k idles mint revs lovely and gives 35-38 mpg and it's coming out soon

[bmw1066]

God that shocking, my 318 touring was a easey 30+mpg.

I get 240 miles out off £43 in a 320 and I drive the poor old car dam hard at time's

[XRMike]

God that shocking, my 318 touring was a easey 30+mpg.

I get 240 miles out off £43 in a 320 and I drive the poor old car dam hard at time's

TBH I think its the luck of the draw with engines in general. You get some good ones and some bad ones. Poor maintenence is a huge player. I got my 318i with no history on 142k miles, it runs like s*it, I rekon its had a hard life and as a result the engine is showing its age now. I cant justify the cost of a head rebuild and a full service when an M50 dosn't cost a great deal more.

[ali-vert]

ive not had enough money since i got my e30 to put a full tank in, ill find out one day

[k13]

my 1988 325i se with mild chip is doing 15.6mpg.

this month its had, all the belts changed, fuel filter, oil and oil filter changed, new radiator, some new water hoeses changed, its even had a squirt of that PowerBoost de-coke stuff in there too and im still recieving 15.6mpg and i drive normally.

[Dezzy]

Filler neck on the tank is my guess again