Effect of Tire Pressure on Efficiency

Many people ignore tire pressure in their day-to-day lives. In a country striving for maximum efficiency, neglecting to maintain correct tire pressure can noticeably affect the amount of horsepower required to overcome the drag forces due to tire/roadway friction. In order to quantify these horsepower changes, 21 test trials were conducted by allowing a test vehicle to coast from 50 mph down to 20 mph at pressures ranging from 50 psi to 20 psi. After compiling the results, it was shown that lower tire pressures increased the horsepower necessary to propel the automobile.