DH, everything is a trade-off. Numerically high gears like your 4.11 will give the best acceleration, but suck at mileage. Lower numerical gears in the high 2's, low 3's (2.73, 3.00 for instance) will give the best mileage, but they suck at acceleration. Most guys will try to achieve a happy medium, around 3.50 to 3.70 if they have a dual purpose car or truck with no overdrive.

Here is a chart that may help, showing some diff widths....
http://www.teufert.net/other/rear%20...dimensions.htm