Evening,

I'm sorry of this is the wrong subforum for this question. I wasn't sure where in belonged.

I have a 91' Firebird Formula and the mpg seems off. I have messed with a few things but I'm still putting in gas far too frequently for what it should be doing (I'm getting around 13-14 mpg). In addition, but perhaps unrelated, when I go to pump gas it clicks before actually filling all the way as if a sensor is off. The guage, when at 3/4th tank, is when it's full. I'm not quite sure what's going on between the two issues so any help would be appreciated.

 

13-14 mpg isn't far off, unless you're only driving on open highways at 55 mph. I get about 15 mpg with mixed in-town/highway daily driving in my '91 RS 305 TBI. If you're not driving it like a little old lady, I wouldn't expect much more than that. And if you are, only a few mpg better.

Don't know what to tell you on the gas gauge, I've only owned 4 cars, all GM, and my '91 RS is the only one that the gas gauge has worked properly in.

 

How many miles in on the car? How are you driving it? What changes have done to the car? My 86 is rated at 18 & 25 mpg, never check mine as it is about the ride / fun not MPG to me.

 

Hmm. My 89 305TBI Firebird even with 3.73s gets right around 25mpgs on highway trips. Im not sure on everyday driving but I would assume 18-20.

 

My old G-van with a 305 and a Q-Jet got about 13-14 in-town and 18-20 on the highway running 70 mph. 700r4 and 3.08 gears. That was staying out of the massive secondaries of the Q-Jet. Open the secondaries and fuel economy dropped like a rock. Something is wrong or the OP has a lead foot.