your e30 is a gas GUZZZLER!

[mr.vang]

on a cold windy morning and i'm going with the wind, i manage to get 40mpg on a flat hwy, going speed limit.

[J308]

Thats actually the equation I used. After my road trip I filled up and it took 12 gallons. It had been 290 miles since my last fill up.

290/12=24.16 mpg

Good to hear. I'll check mine and see what I get.

I wonder what effect lightening has on fuel economy? I'd like to know what the hall-of-fame lightness thread guys get when driving normally.

[Ninz30]

it doesnt matter how much your tank holds. you'll never actually put that in, your tank should never be completely dry. not even possible to suck all the gas out of the tank due to the swirl pot. when your car dies you still have gallon or 2 of gas in there. and some e30s have 16 gallon tanks and some 14.

so... you fill up, let the gas nozzle click off on its own and then drive for a week. you fill up again, let the gas nozzle click off and then take your miles and divide by gallons filled up. it could be 10 gallons you used, or 11. or even 5. w/e. that's how much gas you used.

dividing the miles driven by the maximum hold of your tank is just stupid.

Thats actually the equation I used. After my road trip I filled up and it took 12 gallons. It had been 290 miles since my last fill up.

290/12=24.16 mpg

[Mr. Tasty]

my 318is is a gas guzzler,kinda regret selling my civic that get 450miles on a full tank comparing to my e30.

this. I was able to get 35ish with a 2003 si hatchback on the freeway. About 27 mixed

[FunfGan]

I don't know exactly, but it was NOT good hahah.

[RainierHooker]

My average is somewhere between 9 and 11 l/100km in the eta. I'm scared to think of what it is in the M.

[Kershaw]

it doesnt matter how much your tank holds. you'll never actually put that in, your tank should never be completely dry. not even possible to suck all the gas out of the tank due to the swirl pot. when your car dies you still have gallon or 2 of gas in there. and some e30s have 16 gallon tanks and some 14.

so... you fill up, let the gas nozzle click off on its own and then drive for a week. you fill up again, let the gas nozzle click off and then take your miles and divide by gallons filled up. it could be 10 gallons you used, or 11. or even 5. w/e. that's how much gas you used.

dividing the miles driven by the maximum hold of your tank is just stupid.

[scottinAZ]

Im getting about 23-25 on my cabbie with M40 swap, ZF trans, 2.93 rear end

Light comes on about 300 miles, takes 12-12.5 to fill it up.

[smooth]

I agree with your advice I've heard early fueling is good and according to the e30 manual you shouldn't wait to last minute to fuel up. I did it this once to see exactly how far I could get her.

I forgot you have a cabrio, as well. You have a 16.4 gallon tank like I do. If it's like my old mopars the other gallon or so is in the reserve tank so while your needle went into the red you still had a gallon or two in the tank. I'm not sure how much is left when the warning light comes on but you do have a warning light that will come on after you drive around with your needle in the red.

Our cars (cabrios, not e30's) are substantially heavier than the rest (of e30's, not cars) , too so 18 mpg isn't terrible. btw, that's about what I get with a chip and 91 octane.

I've been driving cars older than my gf for my entire life so I've just learned to live with gas gauges that only tell me how much gas I have when I'm about halfway full. If the needle is to the left I'm either empty or full...all the way to the right and I'm either full or empty :)

or my favorite with my old datsun pickup was that the tank was either E for enough or F for "effed".

[immajackuup]

my 318is is a gas guzzler,kinda regret selling my civic that get 450miles on a full tank comparing to my e30.

[Good & Tight]

My 84 M10 drives 370 miles on 12 gallons. That's close to 31mpg with mixed highway and city driving. Pretty damn good for a 28 year old car, compared to some of the new cars.

[Ninz30]

I'm pretty sure your '91 should have a 16 gallon tank. I wouldn't be so sure that your gas gauge needle is particularly accurate. I'd be more inclined to suspect that your gas gauge is less accurate than your late model having a 14 gal tank...but my cabrio's specs are different from the rest in a lot of ways so this might be one more.

I'd say go by the OBC but I'm not entirely sure it is anymore accurate than the gauge. I don't know where it pulls its signal. The digital output would be theoretically more precise than the analog one, but if the issue is a tired sending unit I'm unsure of the ramifications.

One thing I will say, though, is I try to minimize the amount of times I run below 1/8 tank of gas. Once you start getting to the end of a tank you run the risk of pulling sediment into your fuel filter.

One other thing, if you're trying to gain more mpg, is to fill up in the early morning when gas is more compressed and you'll get denser fuel from the station. I'm too old to drag my butt out of bed for this kind of thing but it's something to remember if you can get into a good fueling regiment instead of just looking around for gas when you're about empty.

I agree with your advice I've heard early fueling is good and according to the e30 manual you shouldn't wait to last minute to fuel up. I did it this once to see exactly how far I could get her.

[smooth]

I'm pretty sure your '91 should have a 16 gallon tank. I wouldn't be so sure that your gas gauge needle is particularly accurate. I'd be more inclined to suspect that your gas gauge is less accurate than your late model having a 14 gal tank...but my cabrio's specs are different from the rest in a lot of ways so this might be one more.

I'd say go by the OBC but I'm not entirely sure it is anymore accurate than the gauge. I don't know where it pulls its signal. The digital output would be theoretically more precise than the analog one, but if the issue is a tired sending unit I'm unsure of the ramifications.

One thing I will say, though, is I try to minimize the amount of times I run below 1/8 tank of gas. Once you start getting to the end of a tank you run the risk of pulling sediment into your fuel filter.

One other thing, if you're trying to gain more mpg, is to fill up in the early morning when gas is more compressed and you'll get denser fuel from the station. I'm too old to drag my butt out of bed for this kind of thing but it's something to remember if you can get into a good fueling regiment instead of just looking around for gas when you're about empty.

[Ninz30]

300 miles on a 16 gallon tank is about 18 mpg. If you fill your tank up, drive your miles for the week, then fill your tank up again, then divide the miles you drove with the gallons it took you to fill up you'll be able to verify your mileage. Do this for a month and then see if you're still getting 25mpg.

Ok so when I hit 290miles off of a full tank my needle was in the red zone. I filled up and the car took 12 gallons then was full again. Is my tank smaller? I don't think I have a 16 gallon tank.

[smooth]

yeah, there's just no way to drive it easy save cruise control on a boring highway so far as I can tell :|