My fuel gauge doesn't work and was wondering how many gallons my tank holds. Oddly, I think I'm getting around 14.5mpg (I've heard others get much worse), and I just want to see how far I can go between fill ups on a long trip.

Thanks.

 

my gsl-se holds 14.5 gallons in the tank

 

Thanks Gregs! Mine should be similar.

 

Actually, the capacity is 16.4 gallons ('81-'85, I believe). The SAs had a 14.5 gal. tank. Gregs, I also thought my SE held 14.5 gal for a long time because even when the gauge reads near E, it never took more than 14 or so gallons. One time it did get really low and it took over 15 gallons, so I know it is a 16.4 gallon tank.

 

well ive filled my car up completley from being bone dry (car ran outta gas on the road) and i was able to squeeze 15 gallons in there and that was with gas almost coming out of the filler.....

-greg

 

Well, then planning for long road trips I'll just assume that the tank is 14.5 gallons. Better safe than pushing!

 

check your haynes manual to confirm but im pretty sure, better to under guess than overguess and get stranded!

 

I coasted into the station bone dry and put in 16.7 gallons.

B

 

Per the 1985 FSM, 16.4 gallons.

 

16.4 gallons may be the theoretical capacity, but a significant portion of the capacity cannot be utilized in practice. Eons ago, when I got my first RX-7 (82 S), I thought because I never was able to fill more than about 14.x gallons there must a big reserve after the gauge reads empty. So, I bravely kept driving as the needle was on the red mark, thinking I had miles remaining to worry about stopping for a fill-up. Damned if that car didn't starve *exactly* as the needle reached the bottom of the read mark, stranding me (fortunately, only a few blocks from a gas station). Lesson learned! When the gauge reads empty, it means EMPTY. I think I got maybe 15 gallons in it that time. Anyway, just remember that not all the capacity can be used, even if it's theoretically available. You will have air pockets at the top and some fuel sloshing around at the bottom that won't syphon out (particularly once the pump sucks any air, like when you turn and fuel sloshes away). Also, it's not a good idea to run a tank dry, as you will syphon any rust/sediment into your fuel filer, potentially clogging it.

 

BTW, the reason the Series I (1979-80) RX-7s had a smaller fuel capacity is because they had a full size spare tire well that the tank is molded around. Later cars had space-saver spares, so the tank could be larger. If a 16.4 gallon tank only gives you 14.x gallons of usable capacity, think how bad it was for the guys with 14.x gallon tanks...

 

Halen,

My gauge doesn't work either. I have the 14.5gal SA, and what I do is use the trip odometer to keep track of where I am on fuel. Whenever I hit 200, I fill up (usually 11-12 gallons).

If you're trying to estimate specifically for a long highway trip, you should be able to add a substantial amount for highway mileage. If it were me, I'd probably refill at 250 (assuming a 16.4gal tank). You could likely go longer, but gas stations are not guaranteed on certain trips. I once had to backtrack 50 miles in Wyoming because there literally wasn't a gas station available.