Yeah but if you're getting 20+MPG from a 318, its basically USING all its fuel rather than spewing unburnt fuel out, meaning that to be doing that well on MPG, it HAS to be burning clean at the same time! My 76 Charger SE with 2.76 gears would get 25 MPG if I kept it on cruise at 62-63 MPH. Yet it seemed by seat of pants to have a "sweet spot" right at 70, and it still got like 21ish on cruise at that speed. But I guess that aerodynamics started to play a part at the higher speed (the car was a "brick") Heck my 87 B 250 van with the 318-2 bbl and the lean burn intact would also get over 20 MPG on the cruise at 62ish; 2.94 gears there, 235 75R 15 Michelins.