Why 4.1 axle?
I tow an 8000 pound trailer with a GMC 2500 with 6.0l engine, 4 speed transmission, and 4.1 axle ratio. I rarely need 3rd gear on the highway; only on steep hills. For my next truck, why not get si...
Forum Discussion
Why lower rear axle gears? Because you have more wheel torque in every gear. If you're only using a 4 speed automatic right now, it'd be even more apparent. You do live on the side of the country that is a lot less steep, however. Take I-70 west from Denver and tell me how those 33" tires and 3.73s are working out for you.
I also think you'd find that all else equal, 3.73 gears would not give you any better mileage than you're currently getting. Your towing mileage would go down almost certainly, whereas your empty mileage would perhaps go up a little, but more likely stay the same. In my truck with 37" tires, going from 4.10 gears to 4.88s--even without any overdrive--the mileage stayed the same. The newer GM engines really like to rev.
I also think you'd find that all else equal, 3.73 gears would not give you any better mileage than you're currently getting. Your towing mileage would go down almost certainly, whereas your empty mileage would perhaps go up a little, but more likely stay the same. In my truck with 37" tires, going from 4.10 gears to 4.88s--even without any overdrive--the mileage stayed the same. The newer GM engines really like to rev.
