Originally Posted by moparrockSRT8
You will have a lot taller final transmission gear but the rear end will be geared lower in the 6-speed than with the autostick. Therefor, the MPG for the auto and the stick should be a wash. Are there any published EPA mileage numbersfor the 6.1 with the manual? Like I said earlier the 6-speed will be a BLAST, MEGA FUN!! But for me personally, that fades big time in city/rush hour traffic. I will throw in a positive item in favor of the 6-speed. Long trem cost of ownership will be better with the 6-speed. It will be $$$ cheaper to replace a fried clutch that a burnt automatic.
I calculated some numbers awhile back on what your rpms would be in the 6speed vs the auto tranny. Here were some of my results:
6 speed was calculated using a 3.91 rear ratio, and the auto was calculated using a 3.06 rear
...............6 speed..............Automatic
Gear.....Speed....RPM.......Speed.....RPM
5th......60mph....2017......60mph.....1800
6th......60mph....1354......N/A.........N/A
6th......80mph....1800......N/A.........N/A
5th......50mph....1726......51mph.....1500
5th......40mph....1380......41mph.....1200