"high" temperature grease have nothing to do with how good of a lubricator they are. Silca gel thickening grease for kiln cars, as an example are usable to 1000 degrees F, but sure wouldn't want it in my car wheel bearings. High temp is a missed used marketing term. imo. Grease come down to thickening agents, percent and quality of base oils and quality and amounts of additives. As with oil, grease should be selected by the application it is to be used.