2 of the good mpg 318 cars I drove/had were an 87 2 bbl 5th ave, and a 2 bbl 72 satellite 2 door. Both got 25 mpg hwy at 65 mph. The lockup on the 87 really dropped the rpms. The 72 sat had a 2 series gear. Everything else I had with 318 was truck-4x4 and ate gas.