On the 04's and up what is the big difference between 3.55 and 3.73? Does the 3.55 get better gas millage and have let pull?

 

Rear axle gears are ratios. The 3.55 for example means the driveshaft turns 3.55 times to make the rear wheels turn once. The lower the gear(the larger the number) will pull harder and cause the engine to have higher rpms at speeds. The taller the gear(the smaller the number) will not have as much power, but will provide higher speeds with lower rpms. Hope this helps.

Robbie

 

with a stock setup no towing 3.55 will get u better highway gas mileage... if u tow.. plan on getting bigger tires... off roading or town driving go with 3.73... these are 2 gear ratios that are so close that if doesnt really matter.. i would go with 3.73 if i had the option but i bought used truck with 3.55 limited slip so its alright... im pushing 33 inch tires in a town that is all hills and i have no problem but 3.73 might give me .25 more mpg.