I know that stainless will be a bit hotter than aluminum but no matter what material you make it out of it will get hot on our cars. I tried to keep the intake as far away from the motor as possiable just for that reason. If I was to put a coating on (paint or something), it would retain heat even more thats why I just polished it. I will get around to see just how hot it does get but I am not in a rush to do that right now, but some day!