Severe Service Challenge Severe service and aggressive riding pose challenges. Elevated heat can break down oil, leading to harmful deposits and placing the engine at risk of extreme wear, while increasing the likelihood that heavily loaded, high-torque gears and bearings will fail. In addition, while accessories increase performance and versatility, the added weight and the propensity of these machines to be used for towing or hauling increase harmful heat and stress on gears and bearings. The negative effects of severe-service riding increase the importance of high-quality lubricants for increased protection.