I was at a neighboring track over the weekend and the topic of tire treatment came up. I asked once about this at our main track and was told its not allowed. However, the racer I talked with at the neighboring track said there is no rule he was aware of and in oval racing they do all sorts of things to tires (this was a sprint race).
I would imagine at regional and national levels its not allowed but likely varies from track to track for club, especially if tires aren’t being durometered.
It’s a whole other realm of voodoo if you really want to get into it. On dirt it’s more varied, for sprint racing you’re usually trying to get the tire softer or to fire up quicker.
Against the rules almost everywhere these days because the chemicals are nasty. But we did it back in the day when it was allowed at the club. Illegal tire prep was a huge issue at WKA national races about 10-15 years ago before they started checking them.
We built a hot box with a rotisserie and filled the tires with prep, let them bake and rotate overnight, and then applied prep to the surface and plastic wrapped them. Definitely worth doing back then on the rock hard club tires. Once you start using a softer tire it sort of stops being as beneficial.
There are lots of different brands and kinds.
Not sure it’s so worth it when you essentially have to have a separate set of wheels and tires for when you visit the other track. Not sure how much a modern tire benefits compared to the old pure rubber tires either.
You can try wiping the tires with WD40. That is a trick used by some oval guys running asphault. When I gave it a try it definately made a difference to the tire (Vega yellow).