bimbert84 wrote:
I think you should evaluate your expectations in changing from a 3.08 to a 3.42.
3.42 / 3.08 ~= 1.11
Tow ratings aside, this means that at any given speed, the 3.42 will put 11% more torque to the wheels and turn 11% higher RPM.
11% is not much of a change IMO. Unless you're having trouble launching from a stop, I'd keep the 3.08 and try downshifting a gear in the transmission. That'll give you a much bigger increase in wheel torque, and best-of-all, it's free.
-- Rob
Rob,
Thanks for the input.
Even if the rating were linear, it would mean that 7000# becomes 7700# which is greater than the GVWR of the RV I am contemplating, while at the same time not impacting my fuel economy as much as a lower gearing would. Since this truck is my daily driver that is very important.
The reality is, if GM can rate their 3.42 geared truck with my configuration at 9600# (+37%) then the relationship is not linear with respect to rating. At the end of the day, I would be going for more than the RV GVWR that the new ratio can give - whatever that margin is - and I still hope to get close to the usual non-towing 17 mpg average I get now.
