Gear Ratio's on Trucks

[summit_man800]

Can some one explain to me what this means to me in lamens terms.

3.73
3.55
4.10

I am under the impression that the numbers refer to how many times the drive line turns in comparison for the wheel turning once. Although I am not sure.
Also what is the best ratio's for pulling? All around good highway and low range, and I am sure MPG is in this mix as well.

 

[ArcticBoy]

Your impression is right. The higher the number the lower the gears. I got 3.73 in my Duramax and tow 20K often and get around 20mpg at 60mph.

 

[ruffryder]

Drive shaft rotations for one drive axle rotation.

4.10 : 1

means that the drive shaft rotates 4.10 times while the wheel rotates only once.

 

[JHG]

The optimal gear ratio is going to depend on a lot of things. engine size, tire size, desired gas mileage, towing in the mountains or flat land. Here's a chart that will help you decide. Remember that the RPM's shown are at a 1:1 ratio which in most automatics is 3rd gear. Over drive is something like 0.7:1 I think. I ran 4.88's w/ 35's on my tahoe and it worked great for towing but was a little low for highway driving. 4.56's would have been prefect. Make sure you measure the tire yourself, the sidewall is usually not correct, 35's are usually only about 34".

 

[summit_man800]

thanks for th graph, that really helps.