I purchased a set of AR Fuels in January which came with steel valve stem caps.The first time I tried to unscrew them to air down in March they were frozen tight, virtually a pain to get off. I've recently found out that AR had a bad batch of steel valve stem caps. The plating covering the caps didn't adhere properly and the two months of Chicago winter weather with all that salt basically locked the threads together. I would assume if you don't live in an area that salts the roads like Chicago you might be fine, but with all the trouble I had I'd call up AR and they will gladly send you replacements. Pass on the news.