Analytical Evaluation of OEM Wheel Combinations that Reduce Sustainable Efforts and Increase Automotive Fleet Operational Costs 2012-01-0648

A current trend by automotive manufacturers involves using tires with a lower aspect ratio, while increasing the rim diameter to effectively maintain the same final drive ratio. The use of larger 16- and 17-inch rims in the design of automobiles is dramatically increasing, especially from American and European automotive manufacturers. This trend is responsible for increased vehicle life cycle costs, increased vehicle fuel consumption and increasing waste and consumption of precious resources, all while reducing commonly monitored sustainable fleet deliverables.

A measurable burden for a fleet based organization is the additional cost associated with purchasing lower profile tires for larger diameter rims. The use of a lower aspect ratio tire will increase the total output of waste which reduces sustainable goals. In order for a manufacturer to maintain the same final drive ratio with lower aspect ratio tires, it is necessary to use a physically larger rim. A physically larger rim is not only heavier, but the mass is concentrated further from the rotational axis, thereby increasing the polar moment of inertia. As the polar moment of inertia increases the vehicle's fuel economy is reduced. Those parameters will increase the consumption of various non-renewable resources and ultimately reduce various sustainable efforts.

This research will analyze the problem based on engineering principles, as well as suggest possible solutions to overcome the inherent issues concerning the use of larger rims and lower aspect ratio tires.