Originally Posted by Greywolf

Wheels are the major 'unsprung weight' load on any vehicle. But they are also highly 'energy absorptive', and there are a number of theories as to how to reduce loading on a drivetrain by cutting the load right at the hubcaps. Any bicyclist knows well the difference between pumping big tires, and running on small diameter high pressure tires (road and touring bikes). The principle does not change just because we are looking at a truck instead of a bicycle - if anything, it brings to us a test sled on which to chase the idea even further...

We should explore this, especially now. What we learn and save could go right into the BANK!

The dynamics of a rotating tire are not what most people think they are. As a tire/wheel rotates, ALL of the mass it is made up of is constantly changing direction - and that requires an energy expenditure. THEREFORE reducing the total mass reduces the amount of energy required in order to just turn the wheel. This energy expenditure increases directly in proportion to increased RPM at the axles.

Bottom line here is that BIG tires should be reserved for slow going and off road use. For the highway - normal width, moderate sidewall, high pressure ('E' rated tires are pressurised to 80 PSI) tires on alloy rims are the best way to go.

NOTE: Taller wheels/tires have a lower overall rotation rate for a given speed of travel in miles/kilometers per hour.

-Comments?