s54 fuel economy

[propr`one]

Ever since i put my 19's on my fuel economy has gone from about 180 miles a tank (indicated) to about 160 miles a tank (indicated). This difference is exaggerated since i'm now running slightly oversize rear tires (245/35/19). My fillups are usually just under 12 gallons which gives me around 13.3 MPG. this seems very low even though i drive very aggressively on the street

car runs great, but likely has 130K miles on the original O2's. Probably time for a change.

What kind of mileage do you get? I'm interested in s54 specifically (coupes and roadies)

edit: i forgot to add i also have a 3.73 diff

[RickySixx6]

230-250 a tank. I suggest you remove the blocks of lead from the trunk.

[Mystikal]

Probably average 225 before the light comes on. Seen as little as 75 and as much as 300 (well, light on at 260 and made it to 300 before filling).

[Bcar]

200-220 when light goes on with a 50/50 mix highway and city.
stock rear end, 18"s.

[Randy Forbes]

3.73:1 also; I usually get around 200 miles, maybe 230 on a trip if I'm behaving.

I have yet to see a set of 19" wheels on one of these that don't look grossly out of proportion__18" is already pushing it. Just my opinion

[ctlynch]

I see about 220-230 depending upon the highway/city mix and how hard I'm on it.

[propr`one]

I have yet to see a set of 19" wheels on one of these that don't look grossly out of proportion__18" is already pushing it. Just my opinion

i can explain the dichotomy of opinion by sharing that i was born in 1987. my girlfriends 16 year old cousin also likes the 19's.





mystikal i hear you're running 315's now?

[Randy Forbes]

i can explain the dichotomy of opinion by sharing that i was born in 1987. my girlfriends 16 year old cousin also likes the 19's.





mystikal i hear you're running 315's now?

I lose sight of the fact that not everyone is as old and set in their ways as I am...

[fmcfad01]

That's way low. I get similar to the 200-250miles per tank depending on how I drive.

[lokijibber]

I get 200 before the light is on and can easily get 250 before filling. Thats with 3.73 gears and 18" 315s on the back. I definitely don't drive like a grandma either. You've got to look into that.

[E.Hands]

3.73 gears, 315 tires, 225-250 before the light, all highway on the original O2's

[Jeremy]

Over 22k miles, I have averaged 19.68 MPG. Late last year I reduced my highway commute, and it dropped to 18.14 MPG. Several tanks of all highway driving on the way to Dorkfest last year brought it up to 21.66 MPG. My lowest yet was 16.68 and that was a lot of heavy footed street driving. I'm running 18" Kinesis wheels with tires close to factory circumference, no drive train mods. 120k miles on my S54.

[MDICTED]

Over 22k miles, I have averaged 19.68 MPG. Late last year I reduced my highway commute, and it dropped to 18.14 MPG. Several tanks of all highway driving on the way to Dorkfest last year brought it up to 21.66 MPG. My lowest yet was 16.68 and that was a lot of heavy footed street driving. I'm running 18" Kinesis wheels with tires close to factory circumference, no drive train mods. 120k miles on my S54.

I'm stealing this and filling it in with my numbers because are cars are almost identical.

Over 14,000 miles, I have averaged 21.57 MPG. My lowest yet was 16.91 and that was a lot of heavy footed street driving and some autocross. My highest yet was 27.56 driving conservatively on a 400 mile trip to Vermont on stock roadstars for that trip. I'm running 18" Kinesis wheels with 295/30/18 tires, and a stock 3.15 LSD. 69k miles on my S54.

Does anyone else have a best mileage? I fill up and reset my tripometer to 0. And fill up til the click when I reset and calculate.

[rboehl]

I just over 4k miles to Las Vegas and back and averaged 230 t o 250 before fillups. I was speeding all the way. All stock by the way. I also never had the light go one before filling up.

[BlueM3Racer]

Ballparking here, but I'd say I typically get about 215-225 miles out of a tank doing 80% city driving. So about 18mpg. Stock 3.15 diff & 18" wheels.

[Randy Forbes]

According to Daniel (dwm) if you're getting >20 MPG you need to turn your car in; you're not driving it right...

Pretty sure the only time I got consistent >20 MPG was the trip home from the factory when the car was new; I closely adhered to the break in guidelines, and was constantly varying the engine speed (you don't break in an engine driving for hours @2800 RPM). Sue was following in the S-52 engined 99, and at every fuel stop, our mileage varied by 1 MPG; if the s-54 got 25, she got 26.

I just can't wrap my head around buying a high performance car, then worrying about the fuel economy__that's what Prius' are for. However, about a half hour ago, I put $86.50 worth of Premium ($4.05/gl) in my wife's X5; if I had to do that very often, I probably would have a different outlook!

[Mystikal]

mystikal i hear you're running 315's now?

Yeah, 315s on Z06 wheels. The looks I get are pretty priceless.

I guess to get back on the thread's topic, both the 3.73 and the 315 tires did zero perceptible difference to my fuel economy. Even when I had the stock diff and 205s all around I was averaging the same 20-22mpg that I am now.

[BimmerDave007]

I very rarely even look at how I'm doing mileage wise in my M. I just fill it up when it's needed.

[lokijibber]

Funny, I just went through the budgeting process for our trip to ZFest and estimated 8 tanks of gas over 6 days. Then I looked up last year's statement... it was 12 tanks in 6 days. That was with the 3.73 and stock wheels. I guess I use more gas than I thought.