(Almost) Utterly Unrelated
But while I've got my "Just do it, dammit" head on...
Please use metal valve caps. You've spent far too much £/$ to rely on the tiniest spring the world ever saw keeping the ever precious air in your tyres. They cost nothing (from an Factory Avon chap at least) and they remove just one of the many, many variables that affect your tyre pressure.
P
Re: Tire scrubbing validation
Geez ! I coulda had a V-8 !!! This is a perfect test question for the Myth Buster guys :) Or, for more fun, Top Gear ! British version. All others need not apply. Better still.... lets get together with our cars & have the tire makers provide each of us with a few sets of their tires, in each compound, at COTA, at their expense, for a week or two of non-stop tire testing. They also supply spares, including engines... & catering.... & 5 Star accommodations...
Re: Tire scrubbing validation
Anecdotally speaking... our local kart track was repaved last fall. The old track was abrasive & fast times were with stickers. This year, new surface is very smooth. Sticker tires are slower. Scrubbed / heat cycled tires are faster.... go figure....
Re: Tire scrubbing validation
All kidding aside... I want to thank Brian for asking the question. Apparently, there is as much art as there is science in our tires. The seemingly infinite number of variables involved with the maunfacture & the proper care & feeding of our tires / tyres is nearly incomprehensible. No wonder the guys I race against who have 30+ years of experience can beat up on me with minor changes in air pressure & chassis tuning. Kudos to all you race gurus !
On the subject of metal valve caps...
I have used them for at least 30 years now. I just don't trust plastic, and I sure don't trust the little check valve to not leak - all it takes is microscopic piece of dirt, and you're done for.
Also, about the same time, because of a wheel-to-wheel-rubbing incident where a metal stem got broken off, I stopped using metal valve stems. I now use only rubber valve stems. In all the races since, they have never caused a problem, or been knocked off in wheel-rubbing incidents.