Bunkie I do the same with Fuelly (my car is listed as Gunner08). I track every fill up.

And yes it does depend how heavy your foot is, how well you can coast, terrain (Kansas or Colorado?), keeping the speed near the posted limit, etc. Use the same grade of gas and use the grade of gas specified by the manufacturer. I run premium in my 4th gen LT1 because they specify that. I can run regular but choose not to.

My 18 year old V8 just got 26.8 on the highway yesterday and I, at times, got up to 90mph. Mostly stayed with the posted speed limit though which was 65-75 on IH35. Of course our 4th gens are lighter and have less HP/TQ than you 5th gen V8 guys. I average about 20 mpg when staying in town (but avoid city stop and go traffic).

 

In my 95 convertible with a six speed I average 18-19 mpg when I travel around my normal routes. Mostly small town traffic and country roads at 50-60 mph in 5th gear or sometimes 6th. I see it rise if I take a trip on the freeway but usually there is city driving at either end of the trip so it rounds down to 23-24 mpg.

I check the mileage almost every tank.

The best I ever recorded was 31 mpg on a long trip on Hwy 5 from Sacramento to Fresno. I was using my cell phone a lot so I was just pottering along in the slow lane at 55-60 mph in 6th gear(yeah I drive like a granny pretty often!). I filled up in Davis near Sacramento and then again right after I got off the freeway in Fresno so the trip was almost 100% freeway miles.

 

This forum, and the entire thread is specific to the 5th Gen Camaro.