Issue link: http://read.dmtmag.com/i/34501
FUEL SAVINGS Tires are a major component in the operating efficiency of the vehicle as a result of their rolling resistance. Rolling resistance is defined as how much effort it takes to roll a tire with a given load and air pressure. This tire rolling resistance is approximately 1⁄ 3 of the total vehicle resistance in 6x4 and 6x2 applications and as such, a change of 3% in rolling resistance equals a 1% change in fuel consumption. Wind resistance and drive line friction account for the balance of the resistance. The MICHELIN ® tires with Advanced Technology ® X One tire in drive and trailer ® ™ compound are built to maximize energy conservation. And the MICHELIN positions can even provide an increase over these Advanced Technology tires. A change in rubber compound can provide a large reduction in rolling resistance, although it is unacceptable to sacrifice durability and wet traction to achieve this result. The Advanced Technology compound is a sophisticated mix of tread design, complex rubber chemistry, and advanced casing design all used while maintaining mileage, wet traction, and durability. As fuel costs continue to increase, fuel expenditures become even more critical than tire expenditures. The ratio of fuel to tire costs will range from 8:1 to 15:1 based on the fleet operation in regional and long haul applications. To calculate potential fuel savings: A. Cost of Fuel/Gal. B. Annual Miles C. MPG of the Vehicle D. Total Estimated Fuel $ _________________________ _________________________ ____________________MPG B ÷ C = gallon _________________________ E. % Fuel Savings % _________________________ F. Estimated Fuel Savings (E x D) = gallon _________________________ (F x A) = $ _________________________ For a more in-depth calculation, consideration should be given to looking at the rolling resistance factors for the specific tires you are considering and ask for the assistance of your MICHELIN Representative in determining the savings. The next step would be to conduct an SAE (Society of Automotive Engineers) Type J1376 fuel test and eliminate all the variables. Again, refer to your MICHELIN Representative for assistance. The SAE Type J1376 Fuel Test is a standard test procedure for evaluating the relative fuel economy of given vehicles. Test cycles are conducted over 2 to 3 days Section Nine: Appendix 125 on a circular route of 30 miles, utilizing two vehicles of similar design and load with fuel supplied by portable tanks. While using the same steer, drive, and trailer tires, a 2% ratio of both circuit time and of fuel weight consumed must be established. All other variables will have been minimized by the constraints of the test procedures. Once the baseline has been established, the test tires will be placed on the test vehicle, and the difference in fuel consumption can be determined based on the completion of 3-5 runs falling within the 2% ratio.