Just wanted to brag on my car a little. First off my setup- 85 Z28 HO w/ L69 305, no ecm, no smog, not cat, msd distributor, Holley 600 carb w/e-choke, edelbrock performer intake, and open element air cleaner. Just finished up my 247 mile trip to college. I started with a full tank of 89 and made it down with 6 gallons left in the tank! 24.7 mpg isn't that bad for a carbureted v8 with no ecm and 180,000 miles! Maybe this is normal gas mileage but it sure surprised me.

 

my v6 doesnt even get that perhaps is my crazy idle issue, (ajust idle for the day its fine to 750 in gear, the next its at 1k rpms ) perhaps its time to invest in a K&N filter

 

How did you determine you have 6 gallons left?

 

filled up before i left, filled up again at the end of my trip and it only took 10 gallons to fill the tank up.

 

That's pretty good. Do you have the TCC lock-up functioning?

A single tank is often not a good judge of fuel consumption, because it's easy to get pump shut-off variation from station-to-station, or even pump-to-pump. But, even if it would have held 11 gallons, or you filled it higher before you left than when you arrived, that's still about 22.5 mpg.

 

I have TCC lockup activated with a vaccum switch. That seems to help out highway MPG quite a bit.