have you thought about going with a T56 (Manual 6 speed)?
it's got a double overdrive
would probably make a difference
but with those 3.23 rear gears, you may need to go 75mph to get peak mpg
my 4,000+lb GTO with a 400HP 6.0L (when stock)
was getting 30-32mpg on the highway (if I could keep the speed up about 70-75mph)
and that's with 3.46 gears
now, she gets about 23-24mpg highway
__________________
2005 GTO 6.0 V8 (600hp)
1991 Geo Metro 1.0 3/5 base
2010 Prius II (replaced 2001 Tahoe 5.3 V8 April 2014)
1994 F-350 7.3 TurboDiesel (Rollin' Coal)
Last edited by KrautBurner; 03-12-2014 at 02:46 PM..
|