Quote:

I have a slant 6 dart automatic and its only getting around 16 mpg , mostly interstate driving some on the back roads. is this average? would a 4 speed overdirve help verymuch? it is winding pretty tight on the interstate but i am not sure of what the gears are in it. and i dont have a tach in it either but it screams right along.

just looking to get some better mileage. i got 16 mpg with my 318 cuda!



Try tuning it up:
1. Adjust the valves
2. Adjust points or better yet, replace points with transistorized ignition
3. Check timing
4. new plugs & wires
5. Check heat valve isn't stuck
6. If equipped, check the EGR
7. rebuild the carb and adjust the floats to spec. Tank the cast parts if possible.
8. Check PCV

I think it should get 19-21. That's what I used to get with my valiant.
Good luck,
Barry