The simplest solution is to just add a surcharge to the purchase of new tires whenever an EV owner buys new tires for the EV (the surcharge would also be imposed when the EV was first sold as new). The surcharge could be based on an estimated per-mile proxy for the gas tax - if one assumed an average of 30 mpg, then the federal gas tax would be about 0.61 cents per mile - and multiply that by the standard lifetime for the tires being purchased (estimated using the treadwear mileage rating). For tires that had a 50,000 mile expected lifetime, that would give rise to a total EV surcharge of $305 for four tires, or about $76.25 per tire. That is not an outrageously high surcharge, and people who can afford an EV should certainly be able to pay the surcharge.