Pick-up Truck Rear End
 

I recently bought a 2005 Chevrolet work truck. I didnt need any options but the one I got came with a heavier suspension and the rear end is a 3.73 instead of the standard 3.23. Would someone interpret this for me? May be a dumb question but I just don't know what the numbers mean.

Thanks,
Kevin

Final drive gear ratios. Ratio, in this case, is 3.73:1...it compares the revolutions of two things...ultimately, I *think* they measure transmission output shaft against wheel rotation.

The higher gear ratio in your truck multiplies torque a little more. That's why many high-number gear ratios like 4.11 are known as "stump-pullers." Higher numbers in a P-car would benefit acceleration, but lower top speed, since it affects how fast your wheels are turning.

Higher rear ratio is going to make your truck a good towing rig. Unloaded, you will have lower fuel mileage, but you can pull a trailer with ease.

As yellowline stated, it's a ratio of how many revolutions the pinion gear/driveshaft must make to get a full revolution of the ring gear/axles/wheels; all else being equal the higher the ratio, the higher the engine RPM at a given speed.

That is if all else is equal. Did the package on your truck include bigger wheels and/or tires? Larger diameter tires will have the same effect is a higher (lower numerically) gear ratio. As an example; I have a Dodge with the factory installed 20" wheels and tires which runs a (low) 3.93:1 ratio, the same truck with the 17" wheel package runs a (higher) 3.54:1 ratio but actually turns slightly more RPM at a given speed because of the difference in tire diameter.

Thanks guys.
928 Ram, It has the standard 17" tires. The reason I asked actually was' I went on a 2000 mile trip last week and averaged 19 mpg. Nothing to brag about but I just got rid of a 2001 truck that was much like this one and the mileage is very similar. I didnt choose the rearend it just happened to come on the truck the dealer found for me.
Thanks Again,
Kevin

I've got the 3.73 in my 2001 silverado instead of the stock gearing. It may get a 1 mpg less mileage but I like the lower gear for pulling a trailer and getting away from stop lights.