over heating problems with schumachers?

I have run them on 3 different cars up to 500 ci and never had a problem, coated and un-coated. One saw lots of street time (30,000 miles) with 2 cross country road trips and 11 second strip passes. Suggestion, only go with high quality in and out coatings.I cheapened up on one set and had to have it re-done.Learned my lesson.