Here's an oldie .....
I have 2 454 4L80E, '92 has 4:10 rear & the '93 has 4:56 gears. Both of my 454 get 14 MPG. The '93 was calculated over a 6700 mile road trip to the Florida Keys & back to San Diego 14 mpg. The '92 was calculated on a 2200 mile trip from Cedar Rapids Iowa to San Diego 14.25 mpg.
Its all how you drive, if you jack rabbit lights or has to be 1st in line your mpg goes down. Easy on the pedal up hills & coast down & you will get good mpg.
With 454's I can just about idle up hills cause of the displacement of the motor.
Last edited by frscke1; January 07th 2017 4:11 pm.