SuperPro Engine Mount Inserts replace the rubber bushes in existing engine mounts with firmer polyurethane. This is more durable than rubber, stops the engine moving excessively under acceleration, enhances traction, and can give more positive gear-changes.Reduces power lossImproves tractionMore positive gear changesEngine mounts are designed to insulate the rest of the car from the normal vibrations of the engine. They need to strike a balance between not letting the engine move too much, and not transmitting unwanted levels of noise and vibration into the cabin. As with many things on the car, they are a compromise, probably leaning more towards comfort than performance.While this suits cars running stock power levels and/or being driven moderately, once you start increasing the torque on offer and/or driving the car harder, the rubber used can prove to be too soft allowing excessive movement.The engine rocking too much under load is a problem because it puts extra load on the exhaus