Water jacket spacer is a unique automotive plastic component, incorporated in the 2006 Toyota Crown and Lexus GS-300.
The component - a water jacket spacer made of DuPont™ Zytel® HTN PPA, is assembled into the engine cylinder block and directs long-life coolant flow to transfer heat and equalize cylinder wall temperatures. This is an application where a plastic is exposed on both sides to hot coolant. The net result is a 1% fuel savings – about 25 liters of fuel per year. If similar fuel saving has to be achieved, the car has to be made lighter by about 25 Kgs. DuPont™ Zytel HTN® PPA was selected in this application for its ability to withstand harsh chemicals, such as long-life coolant, in engine-block working temperatures.
A wider usage of this application in other automobiles will take a longer time but when widely used it would certainly open up a new application of engineering plastic like PPA.