Dodge Durango Forum II Archive

545RFE Tranny Questions...

David B [WI] [99 SLT Plus, LD, 4x4, 5.9, FT, with Intake, TB, MPP, FM 40 Series]
my91bfourc@aol.com

So I read about the new 5-sp auto tranny be offered in the d's mid year. An article I read stated this will be the same one used in the JGC for the past 2 years; i.e. 2 second gears like the 45RFE plus an additional OD.

1st 3.00:1
2nd upshift 1.67:1, 2nd downshift 1.50:1
3rd 1.00:1
4th 0.75:1
5th 0.67:1

My question is that the d's window sticker with the 45RFE gets 18MPG on the highway and the ones with the 545RFE gets 17MPG? What gives? If they are giving me an extra OD I would expect it to get better highway mileage. If not, at least stacking gears 1-4 together (with 4th being the 1.00:1) would be better for acceleration and towing. I know this tranny is scheduled to backup the new HEMI (345hp and 365 ft.lb) so maybe the combination of gearing is designed with that engine in mind?

Any ideas?

Dave

Tue Apr 30