I bought the car in May and have slowly been fixing little things like egr valve,distributor cap and rotor,spark plugs and wires,air filter,brake hose,etc. All the while I would drive to the dragstrrip about 8miles away make 3 or 4 runs then park it in the driveway and drive my old 83 corolla the 3 mile roundtrip to work. Well I finally decided to see what mileage I could get.Had been getting 18 or so going back and forth to the track.So filled it up with premium and drove it easy for 197miles only one 1/4mile blast the rest light throttle driving around town and on the highway at 70mph.Used 6.15 gallons that comes out to 32MPG! I couldn,t believe it. This fuel injected computer controlled stuff really works.

------------------
1990 formula 350 tpi dual cat auto 9 bolt posi 3.27 ratio

 

nice, altho that kind of seems unreal? Weren't the GM MPG rating like 21 or something? and hey if you can get that out a 350 auto i wonder what i can get out of my 305 5speed?!

------------------
1987 Black 305 TPI 5spd IROC, seems to be fully loaded, but can't find RPO codes.

AIM: SzkiRM125
F-bodies : The last with-standing defense against the Invasion.

 

I hope my '89 gets that!! My '79 T/A only gets like 9-11 MPG!!

 

Unfortunately, that is not enough distance to conclude on your mileage. There can be almost a 2-3 gallon difference depending on how you fill. And a further 1/2 gallon difference just due to temperature.

Do a LONG DRIVE where you almost use the entire tank and to ensure you have comparable fills, fill it until the gas is just about to overflow out the filler.

 

32 sounds really nice, but a lil too good for f-bodies I run Chevron 89octane "plus unleaded" and do about 120 mi. on the highway (70mph), and the rest on local streets driving with a "moderate foot"... heavy when neccessary, heh. Anyway, I averaged 18, 17, 17, 19, 21, 19 on my last six tanks... go figure, huh? I'm guessing our cars pull 24mpg on highway, and 16 on local streets. My 2 cents.

------------------
Brian P.
'91 TransAM: 305TPI -=flowed=-

 

You guys are lucky, i have a 305 auto and I'm lucky to get 10mpg.

------------------
1987 Pontiac Trans Am GTA
305 TPI, Auto, T-Top, Digital Dash, etc
http://members.fbody.com/1987GTA/

 

Fuel mileage should be averaged over several tanks to be considered accurate. As mentioned already, there are lots of variables that can affect single tank mileage. The biggest variables I run into are the levelness of the car at the station and how far I top it off.

 

The factory rating was around 16/25 depending on the car and options. Getting over 30 isnt unrealistic but its not easy thats for sure.

 

On my resent trip from Reno to Orange county I got 32 mpg on my converted 305 to TPI with a 5-speed. I got 29 mpg on a trip to Pheonix when it was TBI.

------------------
Chronologically challenged. But still kicking!
'92 CAMARO RS
305 TBI 5/spd (now TPI)
B4C Alt.
'69 camaro-BB/Lenco,1050 dominators, /Pump Gas/no drugs 8.97-150+/3200lbs.
SoCal Thirdgen F-Bodies