This is my first thread on here so please excuse me if this is in the wrong section. I have a 1991 Camaro RS hardtop with the 305 TBI. I have an in tank fuel pump in a tank that seems to hold about 20 gallons. I know 3rd gen camaros have a 14 maybe 16 gallon tank. What kind of fuel tank could I possibly have??

 

AFAIK, there were no fuel tank options for 3rd gens from the factory (1LE, maybe?). Capacity of the stock tank is a bit less than 16 gallons IIRC. If it's an aftermarket replacement, it's anyone's guess.

 

Rated 15.5 gallon, regardless of the engine/trim for the 1991:

 

I've read that the 4th gen plastic tank is larger.

Is your tank plastic?

 

18 gal on the 4th gen plastic tank.

 

4th gen fuel tank is 16.8 gal capacity according to the 2000 Camaro owner manual. I have one in my 3rd gen and have never gotten more than 16 gallons in it.

 

Well i knew it was somewhere in that range. That six escaped my mind, but thats almost 17 gal though, pretty good. Now ive read the 3rd gen tank is 14.4 or am i remembering that wrong too dang it.

 

I get about 150 miles between fill ups.

 

281.6 miles to 13.4 gallons on the GTA with the L98 engine. That is honestly the most I have ever gone on a tank though.

 

One day ill have to figure what my MPT is.

 

Next time I'm offered the big tank option, I think I'll go for one of these.........

 

I apologize for the late response, I've been a little too busy with work this week to get online. I just got under and checked and the fuel tank is metal. I filled up from a 1/8 and put 14.4 gal in it. If my math is correct that should mean it's a 16.5 gal tank. However my tank isn't baffled so the fuel could have been swaying the needle a bit. I know there have been times when I've put 19 gal in it from almost empty. So in order for that to be the case 3/4 = 14.4/X. X=19.2. Still, I don't know what tank it is or if I'm just crazy but I like having a big tank! Sorry for the mathematical rambling haha

 

Throw the math out the window. The fuel gauge is anything but linear, it's hardly even accurate.

 

GM already told you what is the tank capacity, you don't have to figure this out on your own.

It is NOT the volume inside the tank. It is the usable volume inside the tank at the design fill limit so venting and all those kind of things still work. You can overfill the tank and go past that. People that "top off" their tank are overfilling it.

 

...... People that "top off" their tank are overfilling it.......

And then sometimes end up coming here asking questions like "Why does my charcoal canister stink like raw fuel"

 

If the pump showed I'd pumped 19 gallons from bone dry stalled on the side of the road, I'd be looking under the back of the car for a puddle or questioning the accuracy of the pump.

 

I'd love a bigger fuel tank!

 

Well.....you can tell it's kinda by full or kinda by empty - give or take 5 gallons.

 

Generally, it seems like the first half of the tank goes forever. After the 1/2 way mark, it seems to drop faster, and when it hits empty on the gauge, the car will go further than expected before stalling completely. It'd be interesting to plot the mileage vs the gauge to see how inaccurate it is. I suspect it's pretty far off, but a fair enough guideline. When it says it's full, it's relatively full. When it shows 1/8th tank or less, it's time to get gas. At empty you're running on fumes, but the late baffling is very effective right until the tank is dry. Close enough for most folks, but useless for calculating capacity.

 

I've also experienced what you describe on my cars.