Gas mileage 225 Slant 6
Back in the day my first car was a 56 Dodge (54 american but updated) with 230 cu ins side valve six. It got about 8 or 9 mpg. My next car was a 1964 Valiant AP5 225 slant six manual. It had twice the power and was much better on fuel but the best I could get on a run was 15mpg. My next car was an ex police 1973 Valiiant Charger with 265 Hemi and four speed manual. Wow it was a rocket ship compared to the AP5 and would get an easy 26 plus mpg on a run.
