95 Chevy 5.7 averaging 20-30mpg???
I have a 95 Chevy Sliverado k1500 Z71. I have pretty much
touched everything on this car EXCEPT the engine since I
bought it. For some reason, it gets REALLY good gas
mileage. I took a 100 mile round trip, at both highway and
freeway speeds (60-75mpg), and when I got back, I used
the exact same pump on level ground. I put roughly 3.9
gallons in it (averaged 27mpg?!). I though it was a fluke,
until I confirmed it recently. 60 mile round trip, stop-and-go
freeway traffic (basically a parking lot the whole way), and
when I got back... 2.75 gallons (22mpg?!?!). I have no idea
what is going on. The exhaust is custom, made by yours
truely. 2 inch downs to a Y, then a glasspack to 2 1/4
sidedump (02 sensor still there, no cat). It's on slightly
bigger tires, no lift. As it relates to fuel, it has a new tank,
pump, and nylon pressure and return lines underneath and
original lines up to the TBI. I have not so much as touched a
spark plug on this thing. What is going on with this clapped
out OBS chevy?