Pushing a vehicle around the shop can be almost scientific if you take a bathroom scale and press with it against the vehicle bumper.

Get a vehicle moving first, then read on the bathroom scale how many pounds force it takes to move steadily.

If it takes 50 lbs to keep a 5000 lb vehicle in steady speed movement, those tires have 1% rolling resistance.

The best new low RR tires claim about 0.7% with new deep tread. Thats about 39 lbs for a 5500 lb Ram.

I think i will go out and whip together a custom wheelbarrow that uses a Ram 5 on 5.5 wheel in the front, and has a "trapped" digital bathroom scale pressed on by the handlebars.

Would the tire store employees call the police if i wheeled that contraption into their store, and asked for fittings?