INDUSTRIES

Rolling Resistance Factors

Total resistance is made up of two components-grade resistance and rolling resistance. The greater the resistance, the more power required to move the load, the higher the costs of fuel, tires and undercarriage components. You can use rolling resistance factors to help you identify which equipment will be most efficient on your worksite.

Rolling Resistance is a measure of the force that must be overcome to roll or pull a wheel/track over the ground. It is affected most by ground conditions and load—the deeper the wheel/track sinks into the ground, the higher the rolling resistance. Internal friction and tire flexing also add to rolling resistance.

A 2 percent base resistance is quite often used for estimating, however the more accurate your description of ground conditions and load, the more accurate your estimate will be. Find the underfoot description below that best describes your worksite to see the resistance factors you can use for estimating.

Rolling Resistance Percentage Table
Underfoot Description	Tires (bias)	Tires (radial)	Track	Track & Tires
SURFACE A Hard, smooth surface Concrete, cold asphalt or dirt No penetration or flexing	1.5%	1.2%	0.0%	1.0%
SURFACE B Firm, smooth, rolling Flexing slightly under load Maintained, watered	3.0%	2.5%	0.0%	1.8%
SURFACE C Dirt, rutted flexing under load Littl maintenance, no water 1" (25mm) penetration or flexing	4.0%	4.0%	0.0%	2.4%
SURFACE D Dirt, rutted Flexing under load Little maintenance, no water 2" (50mm) penetration or flexing	5.0%	5.0%	0.0%	3.0%
SURFACE E Rutted dirt, soft No stabilization or maintenance 4" (100mm) penetration or flexing	8.0%	8.0%	0.0%	4.8%
SURFACE F Loose gravel At least 6" (150mm) penetration or flexing	10.0%	10.0%	2.0%	7.0%
SURFACE G Rutted dirt, soft No stabilization or maintenance 8" (200mm) penetration or flexing	14.0%	14.0%	5.0%	10.0%
SURFACE H Very soft, muddy, rutted 12" (300mm) penetration or flexing	20.0%	20.0%	8.0%	15.0%