RussRPJ

Quick question. The owner's manual for my car lists the fuel tank capacity as 21.7 gallons. I have seen other spec sheets (including that 4-volume shop manual) list it as 17.1 gallons. I treat my gas gauge as a "relative device". In other words, you can only tell in a relative way how much gas is left. Even when full, that gauge never goes to 4/4. Anyway, back on track, just what is the true capacity of the gas tank on the 85.5 models and beyond? Would be nice to know.

Plum

Believe the 85.5 model changes included expanding the tank from 17.1 to 21.7.

snappy

i have a '86 944 and i have a 21.7 gal tank. The best i got was 568miles out of a tank. and i think there moght have been almost a galon left . as when i filed up it took 20.8 galons.

RussRPJ

Thanks. Going to take it to near empty and then fill up. Should give me a cross reference of where I'm at on the gas gauge with how much gas is left, assuming the 21.7 max. Snappy, you're getting a little over 27 mpg with those numbers. Not bad. Was that mainly city, rural or a mix? Not only is my gas gauge flaky, but the trip meter won't reset either. Pesky gauges! So, I'll just write down odometer mileage when I next fillup, drive it out, get the new mileage by subtracting, and then divide that by the amount of gas the car took. Should give me fairly good idea of mpg.

IceShark

Drawing the tank down to near empty may not be the best for your fuel filter if you have any crud in the tank.

Dal Heger

Isn't it 21.1 gallons?
And you're always drawing from the bottom of the tank, that's where the fuel pickup is!

Dal.

RussRPJ

I think this might be a good time to change out the fuel filter. I don't see it listed in the maintenance history. If you draw from the tank's bottom, then you will get any crud that's sitting in the tank into the fuel lines, injectors, and plugs if its there. Yuck!

Well, took the gas gauge down until it just entered the red and then filled up. I could only get 17.3 gallons into the tank, all the way to the top. So, one of 2 things is true. The tank holds about 2 1/2 to 3 extra gallons that only registers in the red, or they put an early model gas tank on my car. Assuming the first one to be true, perhaps I'll take a gallon of gas with me in a can, and run that thing completely dry. Probably not too good on it, but that's likely the only way I'll know.

Melchior

The tank IS 21.1 gallons, trust me! I put a one gallon portable gas tank in my car and drove until the car started sputtering. It stays in the "red" for a scary-long time. The low fuel light on my '90 944S2 doesn't come on until the needle is below the red line. My '87 951's light came on just before it touched the red line. Both have/had 21.1 gallon tanks.

RussRPJ

Thanks Dave. OK, 21.1 gal it is. Still going to do the portable-can test, just to get a feel for how much is left when you're in the "red zone". Looks to be near 3 gallons. But, even driving around in the red for a couple of days, my fuel light never did come on. Could be out.

DinoEck

Ha! The things you learn on Rennlist!

I just got my '89 S2 and have been dutifully filling it up every ~250 miles, which is when the gauge reads 1/4 tank. Been getting 21 MPG.

I guess I've been carrying around some bonus fuel I didn't know about, somewhere around 9 gallons of it!

Noah

RussRPJ

Sho 'nuff. That's why I'm glad there's an internet community like this. There's only one Porsche dealership in my state, 350 miles north of me. And they won't answer any questions unless you hand them some cash! Another benefit of doing the take-it-to-dry test is getting a true mpg. These are funky gauges. So you can use the gauge on the gas delivery tank along with odometer to get a true number. Guy I bought it from told me it was a 30 mpg-plus vehicle. But I wonder.......

adrian_jaye

80 litres, including 8 litres for the reserve tank,

when the warning light comes on to full fillup is 72.xx litres

so far on Shell Optimax on a Full tank have got 342 miles

M758

Early cars have smaller steel tank. 85.5 and up cars (incuding turbos) have the larger plastic tank.

gilwong

The tank is 80 litres. My red warning light comes on when is 13 litres left in the tank (i.e. a fill up is 67 litres). Question of 17 gallons versus 21 gallons? Both are correct. 80 litres is equivalent to 21 U.S. Gallons or 17 Imperial Gallons (used in Britain, Canada (where I'm from), Australia, and other former members of the British Empire). Also, that's why our MPG figures are going to be different from our U.S. friends.

The reserve of 13 litres is about 3.5 U.S. gallons, so you have about 50 miles before you run out of gas!

Ciao.

Luis de Prat

gilwong, you are correct only the early cars DID have smaller fuel tanks than the post-85.5 cars.

The cars don't look like they have the capacity to carry so much fuel, either. I often get funny looks or comments from gas station attendants when I go to pay.