Review on High-Quality Brass (8 Pack) Tire Valve Caps - Silver | Universal Fit for Cars, SUVs, Bikes, Trucks, Motorcycles | Dust Proof Covers with Premium Metal Rubber Seal Tire Valve Stem Caps by Alan Massey

After using aluminum valve stems, I found that they have problems with the dispersion of two different metals; From now on I only use brass on brass. Aluminum is welded to brass, so we've tried to warn anyone buying cheaper valve stem caps not to just buy plastic or brass, as these won't destroy the valve stems. Forewarned is armed! Don't go cheap as replacing valve stems will cost you a lot. Newer cars have "low tire pressure sensors" and cost about $100 to replace if they fail. ;-)