Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - Rolling Resistance Crr / RRC for specific Tires

thorpie · 06-05-2011, 04:22 AM

Hello
The basic formula for the force required to travel at a particular speed is dragCoefficient*frontalArea*airDensityConstant*spe ed^2 + rollingResistance(CRR)*mass*speed. This rolling resistance (CRR) is different to the tire rolling resistance. It includes calculations relating to both the tire resistance and the road surface resistance.
A polished concrete road (at 0.012) has much less resistance than a dirt road (at 0.1) and sand at (0.15 to 0.35) is much higher again.
Can anyone advise how is CRR calculated from the tire rolling resistance and the surface rolling resistance?

06-05-2011, 04:22 AM	#6 (permalink)
thorpie EcoModding Lurker Join Date: Jul 2008 Location: oz Posts: 24 Thanks: 0 Thanked 2 Times in 1 Post	How do you convert to rolling resistance? Hello The basic formula for the force required to travel at a particular speed is dragCoefficientfrontalAreaairDensityConstantspe ed^2 + rollingResistance(CRR)mass*speed. This rolling resistance (CRR) is different to the tire rolling resistance. It includes calculations relating to both the tire resistance and the road surface resistance. A polished concrete road (at 0.012) has much less resistance than a dirt road (at 0.1) and sand at (0.15 to 0.35) is much higher again. Can anyone advise how is CRR calculated from the tire rolling resistance and the surface rolling resistance?