Gas Mileage

[fastair]

Update: Spent this summer doing a complete refresh of the rear suspension. While I was in there I also removed the intake for painting and rebuilding the injectors. One of the injectors was leaking when pressurized, so it was replaced. My gas mileage has increased by about 6 mpg and I no longer have a rich exhaust smell.

[doctorx]

87 325i converible. After running a full tank out and all the repairs, i got 23.5 mpg with a mix of highway and town. running 93 octane because the dinian chip requires min of 91. 91 does not seem to exist here.

[uturn]

Stock 1989 m20 motor w/5spd trans, 4.10 lsd on 87 pump gas - 22mpg on average. Just reinstalled my Yakima rack w/wind deflector, my new average is now 20mpg.

[r-mm]

M20 5sp dont know/stock for my ‘89 87 octane


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[ELVA164]

After a comprehensive re-seal, valve adjustment, injector cleaning, etc etc I'm regularly seeing ~23.5MPG in a mix of fast highway and town driving. Only modifications a light flywheel, stage .5 Squid chip, stainless stock style exhaust.

Engine? Gearbox? Rear end ratio? Fuel octane?

[ELVA164]

In Daytona I get 150 miles on a 16gal tank with a 180whp m20, or 1:45hr...

but that's avg of 90mph per lap, max velocity 147mph. lol

Car isn't street legal.

helpful

:D

[r-mm]

After a comprehensive re-seal, valve adjustment, injector cleaning, etc etc I'm regularly seeing ~23.5MPG in a mix of fast highway and town driving. Only modifications a light flywheel, stage .5 Squid chip, stainless stock style exhaust.

[MontFenn]

What in your opinion is causing this decrease? Normal engine wear or is it time for new fuel system parts?

I assumed it was engine wear, but I don't know.

[ForcedFirebird]

In Daytona I get 150 miles on a 16gal tank with a 180whp m20, or 1:45hr...

but that's avg of 90mph per lap, max velocity 147mph. lol

Car isn't street legal.

[jeffnhiscars]

i believe the pump is cooled from fuel going through it not really around it.

took a pic changing out the pump.
This is with needle at the red.

On the red by jet jones, on Flickr

It's the in tank pump that's cooled by fuel.

I get shit mileage in my cabrio (5spd, 19lb injectors, SSquid Chip). I just tell myself if I can't afford the gas I can't afford an e30...but then I'd be taking the bus which costs even more

[Sonny]

I get about 8km per litre (18.8mpg) with my 4cyl M40 engine. It used to do around 10km to the litre many years ago (23.5mpg).

What in your opinion is causing this decrease? Normal engine wear or is it time for new fuel system parts?

[MontFenn]

I get about 8km per litre (18.8mpg) with my 4cyl M40 engine. It used to do around 10km to the litre many years ago (23.5mpg).

[LowR3V'in]

i believe the pump is cooled from fuel going through it not really around it.

took a pic changing out the pump.
This is with needle at the red.

On the red by jet jones, on Flickr

[ELVA164]

ya it turns on at 1.6.
16.4gal tank so run it to the light and fill up.
run it back down to the light and count the trip.

will give you your actual mpg not some estimate.

m30 turbo on e85 i estimate about 13mpg based on the couple times
i like to fill. usually when the needle's on "empty", yet only 12gals go in.

You don't have to go that low (re: fuel pump heat mentioned before). Just fill it to the click, reset the odometer, drive any distance you want down to 1/4 tank on the gauge, then fill to the click again. Gallons are on the receipt, miles are on the odometer.

[325e '87]

I have never seen a fuel lite on in my 89 - is there not one? Does it come on @ reserve?

One of the first things i checked when we got our cars a couple years ago. You’ll want to confirm that the light does work, so run it down. Just make sure you have a plan to get rescued in case the little amber light doesn’t work.