The base design of commercial vehicle wheel end systems has changed very little over the past 50 years. Current bearings for R-drive and trailer wheel end systems were designed between the 1920's and the 1960's and designs have essentially remained the same. Over the same period of time, considerable gains have been made in bearing design, manufacturing capabilities and materials science. These gains allow for the opportunity to significantly increase bearing load capacity and improve efficiency.Government emissions regulations and the need for fuel efficiency improvements in truck fleets are driving the opportunity for redesigned wheel end systems. The EPA and NHTSA standard requires up to 23% reduction in emissions and fuel consumption by 2017 relative to the 2010 baseline for heavy-duty tractor combinations.This paper summarizes the history of current wheel end bearing designs and the opportunity for change to lighter-weight, cooler-running and more fuel-efficient wheel bearing designs to help meet the new industry standards. Advanced design and modeling principles were applied to analyze improvements, leading to optimized designs. Physical testing validated that these new bearing designs can increase efficiency and reduce weight.