Stupid question but what are the differences between the two diferent ratios. Which is better for towing or mpg

 

373 would be better for highway mileage but 411 is better for acceleration/towing. if you drive more highway then the 373 would be better for you 411 is better for intown

 

Differential gear ratios determine how many times the drive shaft (pinion) rotates per each revolution of your wheels (or ring gear). So, for example, if you have a 3.73:1 gear ratio, the driveshaft turns 3.73 times for ever rotation of the tire.

The higher the number, the lower the gear ratio, so a 4.10 gear ratio is considered a lower gear ratio than a 3.73 ring and pinion. Lower gear ratios turn more RPMs than mathimatically higher gear ratios, putting the engine into the powerband sooner and keeping it there longer, so you end up with more power and torque at any given speed.

Traditionally, lower ratios are more desirable for larger than stock tires, towing or hauling applications. Also, because the engine RPMs are into the powerband sooner, city or stop and go driving conditions are better optimized, resulting in better fuel economy.
Higher ratio's are better for freeway driving as at cruising speeds your RPM's are lower...

 

go for the 4.11s. rams are too big and too heavy for 3.73s

 

I think he's already got the truck 'Feej. He's got 9 posts and 7 of them have to do with MPG mods. Me thinks he's trying to squeeze a couple more MPGs outta his MegaCab...

 

The problem with changing gears solely for mpg is that you need to drive the truck 50 bazillion miles to ever recoup the cost of a gear swap.

 

Exactly, most mods done solely for MPG reasons will take forever to even out, although with the cost of gears, your great grandson might see the reward. LOL...

I still think the only one you got a shot at coming out ahead with if you are looking to mod solely for mpg gains is an e-fan...

 

ive got 3.73s in my 2500, they are pretty lame for that heavy of a truck. (your mega cab is on a 2500 frame). i cant wait to swap em out for something taller.

 

ive got 3.55s in my 4.7 and that is not a winning combo. Yeah it might be good on the highway, i turn like 1600 at 70 mph but if my truck even looks at a hill its downshiftin and it still slows down to 65. im gettin 35s and for about a week ill be with the stock 3.55s..... so that will be a really fun week! im goin 4.56 and i get to pay for both axles! hell if i could id go to 4.88s or somethin

 

My 3.92's with 33" tires cruises 70mph @ 2000rpm in 5th gear.
I may go 4.56 one day.