When I bought my 05 4x43500 srw 2 years ago the one I bought had the 4.10 gears. I wanted the 3.75's but for what I bought the truck for I took the 4.10. My truck is still stock and will probably stay thet way. I was always concerned about the fuel milage of the 4.10. Now with diesel being .35 higher than gas I'm more concerned. I do some heavy towing but not much, and think I could stand the 3.75 gears. I'm currently getting between 15.8 and 16.2 mpg. I have gotten as high as 17 if speeds are keep at 55 or below. I haven't tried drews brew yet , but I'm getting ready to try some .

My question is what calculated milages are you seeing between the 3.75 and the 4.10?

If the 3.75 is better would the difference ever pay for a gear swap?

Thanks for your help!!

 

it would take a while to pay yourself back for a gear swap. . .Ive got 4.10's in my 2500 4x4. . .if I'm easy I can nudge 19mpg. however I mostly average high 17's so your not far off.

Ive thought of one of those gear vender/US gear overdrive units, but the 3K price tag is what gets me. you would actualy be better off keeping the gears, and possably going to a 33 or 35 inch tire then resetting the speedometer since I believe it is 35's that will take 4.10's and give them the final engine speed of 3.73's w/31's.

 

You know that sounds really good, I even tried using that arguement on the wife. Gee honey if I put on the 35 inch tires it would help the gear ratio on the truck, maybe even get me better mileage. I don't know why, but for some reason she didn't by if?

 

i have the 4:10's and my mileage is a little diffrent than the rest with the 4:10..... i get around 12.5 in the city and MAYBE 14 on the highway going about 70-75. but it seems that most with 4:10's have alright numbers[:-]

 

were does it say what gear ratio you have, i havent really looked that hard but i just kinda figured i have 4:10's what ever i have im turning about 1800 rpm at 60mph and im getting around 20mpg

 

Chrysler has publicly announced that they will soon have a 3.42 ratio option for the American Axle diffs that will give better highway cruise MPG for the Cummins Rams.

This is the new gearset that ex-Chrysler VP and now GM VP Bob Lutz demanded that American Axle build.

 

all 05.5's and up with the G56 transmission have 3.73's in the axels. the only way to get 4.10's is with the 48RE auto.