Most of my experiences with piston coatings in racing applications is negligible compared to having bearings coated, as far as manufactureres claims for any gain. For many years, Speed Pro and Sealed Power have offered many of their pistons with coated skirts, and I've noticed that after several months of driving some have showed signs of the coating being worn completely off on some and not on others, but with no visible harm done to the piston itself. Whether coating companies marketing for those services is all hype or actual, who knows, Im sure there are those who might have truly experienced some form of longevity or performance gain that they attribute to the coating of the pistons and chambers or other components they had,but I have really only seen gains from having bearings coated, and that is mostly in the longevity department, and not from a real HP or ET gain. So, is it worth it, I think that companies that specialize in coatings have done testing in many areas(Automotive, Industrial, Aviation) and have come to a conclusion it does work in some way in these areas. Whether it is for a thermal barrier, or heat retention, or other claim they advertise, I guess you just have to ask if the cost justifies the benefits you are seeking it to do for you, and your expectations of it.
