Rolling resistance of electric-vehicle tires from track tests

Technical Report · Tue Jun 01 04:00:00 EDT 1982

OSTI ID:5324164

Dustin, M O; Slavik, R J

Two sets of low-rolling-resistance tires were track tested to obtain realistic tire characteristics for use in programming the Road Load Simulator, a special dynamometer facility located at the NASA Lewis Research Center. One set was specially made by Goodyear Tire and Rubber Company for DOE's ETV-1 electric vehicle, and the other was a set of standard commercial automotive tires. The tests were conducted over an ambient temperature range of 15/sup 0/ to 32/sup 0/C (59/sup 0/ to 89/sup 0/F) and with tire pressures of 207 and 276 kPa (30 and 40 psi). Both sets of tires had very low rolling resistance. The commercial tires, which were manufactured approximately 3 years after the electric vehicle tires, exhibited lower rolling resistance than the electric vehicle tires. This is a result of the continuing effort by the tire manufacturers to reduce rolling resistance in order to improve fuel economy. At a contained-air temperature of 38/sup 0/C (100/sup 0/F) and a pressure of 207 kPa (30 psi), the resistance of the electric vehicle tires was 0.0102 kilogram per kilogram of vehicle weight and the resistance of the commercial tires was 0.0088 kilogram per kilogram of vehicle weight. At a contained-air temperature of 38/sup 0/C (100/sup 0/F) and a pressure of 276 kPa (40 psi), the resistance of the electric vehicle tires was 0.009 kilogram per kilogram of vehicle weight and the resistance of the commercial tires was 0.0074 kilogram per kilogram of vehicle weight. The average time for the tires to reach an equilibrium temperature after startup was 20 minutes for the constant-speed tests regardless of vehicle speed and 27 minutes for the SAE J227a Schedule D driving cycle tests. The average change in rolling resistance from startup to final equilibrium value was 5% for all tests. There was very little heating of the tires from velocity-dependent losses. The predominant heating source for these tires was radiation heating from the Sun.

• Research Organization: National Aeronautics and Space Administration, Cleveland, OH (USA). Lewis Research Center
• DOE Contract Number: AI01-77CS51044
• OSTI ID: 5324164
• Report Number(s): DOE/NASA/51044-24; NASA-TM-82836; ON: DE82018635
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330300* -- Advanced Propulsion Systems-- Electric-Powered Systems
330601 -- Vehicle Design Factors-- Body & Chassis
DATA
ELECTRIC-POWERED VEHICLES
EXPERIMENTAL DATA
FRICTION
HEATING
INFORMATION
NUMERICAL DATA
ROLLING FRICTION
TIRES
VEHICLES