Which Tremec TKX Do I Get

mbaird what first gear ratio do you run at the strip and how bad are your 60 foots. dano the quicker mustangs at the track all ran those transmissions with a minimum of 3.73 rear gear. Your cruise rpm and fuel economy will be based more on were your engine rpm wants to be, for instants I bought a new Durango in 2003 with a 4.7 and 3.55 gears, it had the 265/70/16 tires on it. At 65 to 70 mph it wood get 15 to 16 mpg at 85 to 90 mph it wood get 20 to 21 mpg, that engine preferred to run at over 2000 rpm than under 2000. I have an Eco Diesel truck with 3.55 gears now and that gets its best mileage between 55 and 65 mph at 70 and over it drops 2 to 3 mpg, it prefers to be under 2000 rpm's. Every engine is different and the engine will dictate were its best efficiency is not the gear ratio you think it should be. My Dart smooths out, quiets down and pers like a kitten between 3000 and 3200 and that is its efficiency rpm range, it's between 60 and 63 mph.