Going up hills
I'm new at rv-ing. Just bought a 24' Forest River EVO TT; I have a 2012 Silverado 1500 4WD Crew Cab short box. It has the tow package, Model K10543, 3.08 gear ratio, 5.3L V8. I I'm getting air bags in...
Forum Discussion
SoCalDesertRider wrote:
335 lb-ft x 3.08 = 1032 lb-ft
335 lb-ft x 4.56 = 1528 lb-ft
That's an ~500 lb-ft and 150 percent increase in torque at the rear wheels.
This is sort of true but not in the context of the discussion.
If you are talking about the ultimate ability to keep the rig moving with a heavy load up a steep hill...Yes, the 4.56 will keep moving when the 3.08 has ground to a halt.
BUT, that's not the issue being discussed. The OP never indicated that the truck couldn't make it up the hills, just that it used more RPM than he was comfortable with.
With the really old 3 speed transmissions, once you could hold top gear, the move to 2nd was a big jump in gear ratio and it was often difficult to keep the engine at the ideal RPM range with a limited selection of gears.
With the newer transmissions have 6 or even 8 gears to choose from, they are much better able to match the gear ratio (total including transmission and differential) to the engines ideal RPM range. So while the 3.08 may be running a gear lower (maybe two), the engine RPM will be pretty close to what the 4.56 is running...and the net effect is the sound and feel will be very similar. The engine will be experiencing roughly the same level of stress.
As long as he isn't doing a lot of mountain towing and it's not hunting at every little overpass, the 3.08 is probably a good option as he will get better MPG when not towing which typically makes up the vast majority of miles driven.
