Gear ratio / tire size calculation - help please

[markrinker]

What would optimal cruising speed be for a C4500 Kodiak with 4.44 gears and 225 70R 19.5 radials?

No wheelwells to contend with, and 2WD so I should be able to adjust rear tires to optimize desired tow capability vs. top highway speeds.

(I have intentionally double posted this in the 6.5 section as well as under the Duramax section, as more 6.5 owners have experimented with larger tire sizes and know the calcs and realities of rolling resistance, etc.)

[More Power]

Download this file to your hard drive (http://www.thedieselpage.com/members/RPMPROG.001) then change the name to RPMPROG.XLS.

This is Member Paul Rowland's RPM/Gearing Calculator Excel Spreadsheet that'll allow you to play with all sorts of gearing and tire diameters.

MP

[Craig M]

Talked with a gentleman a few months ago. He had a 3500 Duramax dually with 19.5 tires. Had Alcoa classic 10 hole aluminum wheels and steel adaptors. He did not lift the suspension on the truck. It fit and looked excellent. He was happy with it. He hauled a heavy RV trailer (a 5th wheel if I recall). Kept the standard (3.63 I think) gears.