I have an 86 camaro with a 305. Slightly upraded cam (we suspect), and rebuilt top end. 500 (mabye 600) cfm holley carb. I'm getting 12-13 miles to the gallon using regular fuel.
It's only a 305.. shouldn't I be getting better mileage?

 

What do you have for rear gears? I have 2.77 in my 91 305 TBI and I can get 22 highway (with some spirited driving) in O.D.

 

To be honest, I don't know what rear gears are, haha.
I'm a little new with the whole engine building and whatnot.

 

bumpppp.

someone has to know how i can get better mileage?!

 

get a v6

 

haha.

well MadMike says he gets 22 with a 305 and i'm getting only 13 with the same engine.
What do rear gears have to do with it?

 

My 1990 RS 305 with 239,9xx miles gets about 17~19mpg highway. My suggestion is (if you haven't already) get an upgraded air intake. I went from the stock to a K&N filter and used some cleaner through my intake & vaccum lines and gained 3~4mpg average. If I keep the RPMs below 2500 at all times with minimal throttle I can average city/highway @ 16~18mpg. Which isn't bad considering the age of my engine and the fact that it is a V8.

 

by the math ive done i get round 15 mpg with an open exhaust.
and its sputtering and the tach is hopping all over.

 

I fill up my tank with Hi-test every 2-months if I need it or not....[sm=gears.gif]

[IMG]local://upfiles/2696/BEE19B1236544DC59873EB6A72E670A4.jpg[/IMG]

 

I always use the mid grade unless I am feeling spendy.
With the 2.77 rear gears the engine rpms are low. Low rpms = less fuel being used.