Powerflex Upper Engine Mount Insert PFF85-1821PFF85 1821 acts to stiffen the voiding of the OE mount, helping to restore a level of responsiveness expected from a hot hatch. Made using our Yellow 70A durometer material, it provides the perfect balance between compliance and stiffness, giving control and precision without compromising comfort. A small increase in NVH, usually at idle should be expected when stiffening the mounting between the engine transmission and chassis. The harder the