"So I filled up tonight and calculated that I’m getting 13.7 mpg. Is that good or just acceptable and I could be doing better?"
I'd say that's about right. No mention on how the miles were accumulated, but I'd guess low speed country/city driving for short distances.
My 3600 with a .72 5th gear T5 and original 4.57 rear gears and a pretty good condition 216 averaged 16 to 20 mpg on a 1,300 mile trip to Luckenbach Tx last spring. Mileage was really affected by hills and wind. Head wind bad...tail wind very good for mileage.
Good Luck, RonR
