Rim protectors on alloy wheels
An alloy wheel, in Michelin's words, is an aluminium rim set against a sheet-metal one. A rim protector is a piece you add to the lip. It is not a new wheel, and we haven't fitted one to see how it wears.
What is an alloy wheel?
Michelin, writing about a change of tire size, says changing the diameter means replacing the rims. Those rims "can be made of sheet metal, like the original ones, or of aluminium, which is lighter and more attractive." That is their description of the metal, not a fit chart for a protector.
Tesla's Model Y owner's manual defines the rim as "the metal support for a tire, or tire and tube, upon which the tire beads are seated." The same page says the two-digit number in the tire size is the wheel diameter in inches. So in 255/40R20, the 20 is the rim diameter. Width and offset are separate columns in Tesla's wheel table. A listing that only says 20 inch is talking about that diameter.
Does a rim protector replace the wheel?
No. The protector sits on the outer lip, where a curb meets the wheel. The alloy wheel stays on the car. A full cover over the face is a different part, and so is a repair of metal that is already scraped. Alloy wheel or a rim protector? keeps that split short.
Which wheels does AlloyGator say it fits?
AlloyGator's French page says the ring mounts on aluminum wheels only, not steel, and only from 12 to 24 inches. Every kit includes a test tab for the gap between the outer edge of the rim and the start of the sidewall. Green still showing, or only to the black line, is their compatible mark. Red means they say it does not fit. They name the Model 3 Performance Überturbine as one rim that needs that check.
Their UK page says some wheel and tire combinations suit the product better than others, and that the gauge in the box is the check before you try to fit it. They also say they don't recommend the ring on a vehicle over 2,500 kg, including a lighter vehicle once people and luggage push it over that weight, because the profile could move.
Steel wheels and hubcaps are a separate question. Do rim protectors fit steel wheels or hubcaps?
Wheel size · AlloyGator · Color · Wheel and rim words · How to measure a wheel · A rim protector on a diamond-cut wheel