Choosing alloy wheel protectors by diameter starts with knowing whether the AlloyGator set is compatible with your wheels — from 12 to 24 inches, the answer is yes in virtually every case.
What remains is understanding how to read the markings on your rim or tyre, which specific cases may raise questions (concave profile, oversized caliper), and why 17, 18 and 19-inch diameters alone account for the vast majority of enquiries. This guide addresses each point directly, without detour.
How to read your rim or tyre diameter
The diameter can be found in two places:
- On the tyre sidewall — e.g. 225/45 R18: the number after the "R" indicates the rim diameter in inches.
- On the rim itself — e.g. 8J × 18 H2 ET45: same convention, the central number is the diameter.
Both values must be identical. If in doubt, the marking engraved or embossed on the inner face of the rim is the definitive reference. No physical measurement is required: the marking alone is sufficient to order or configure your set.
AlloyGator set compatibility by size: from 12 to 24 inches
The AlloyGator profile adapts to the width of the rim flange, not solely to its diameter. The compatibility range therefore covers:
| Diameter | Typical vehicles | Note |
|---|---|---|
| 12" – 14" | City cars, light commercial vehicles | Narrow steel or alloy rim |
| 15" – 16" | Hatchbacks, entry-level MPVs | Standard |
| 17 inches | Saloons, compact SUVs (Golf, 308, Clio RS…) | Most common size in France |
| 18 inches | SUVs, premium saloons (Audi A3/A4, BMW 3 Series…) | Flange often wider — check rim width |
| 19 inches | Premium SUVs, sports cars (Cupra Formentor, BMW X3/X5…) | Low-profile tyres are common: fitting is more delicate but perfectly achievable |
| 20" – 24" | High-end SUVs, Bentley, heavy commercial vehicles | Confirm rim width before ordering |
Each set includes 4 profiles + fitting kit. Alloy wheel protection for 17- and 18-inch diameter rims accounts for approximately 70% of all fittings carried out by the AlloyGator approved fitter network in France.
Special cases: concave rims and oversized brake callipers
Concave-profile rims. Some sports rims feature a lip that curves inward. The AlloyGator profile is fitted to the visible outer lip: as long as this lip is accessible and of standard thickness, fitting remains possible. If in any doubt, an approved fitter can check in a 5-minute visit.
Oversized brake callipers. On vehicles fitted with high-performance braking systems (M packs, AMG, aftermarket Brembo), the calliper may sit very close to the rim. Because the profile sits between the tyre and the outer lip — not between the rim and the calliper — there is no mechanical constraint related to calliper size. Fitting is not affected.
Mirror-polished alloy wheels. The profile protects precisely the rim edge exposed to kerbs. On a diamond-cut or polished finish, protection is all the more justified: repairing this type of surface costs between €80 and €150 per wheel at a specialist bodyshop, compared with approximately €99 for a complete fitted set.
Alloy wheel protection for 17, 18 and 19 inches: specific points to watch
These three diameters account for the majority of enquiries, as they are fitted to most vehicles sold in France since 2015. A few practical distinctions:
- 17 inches: tyre profile is often higher (45 to 55), which makes partial dismounting easier during fitting. Fitting time: 45 to 60 minutes.
- 18 inches: the rim lip is sometimes wider on SUVs — the approved fitter adjusts the profile accordingly during fitting, at no extra cost.
- 19 inches: very low-profile tyres (35 to 40) are common on Audi or the Alfa Romeo sports models. The lip is more exposed to kerb impacts: this is precisely the use case that makes protection a priority.
FAQ
Is the AlloyGator set the same regardless of rim diameter?
The profile is available in several widths and lengths to suit the geometry of the lip, not the diameter itself. The diameter determines the number of sections to be cut, not the type of profile. Your approved fitter will determine the correct configuration during fitting, which is included in the price.
Can I fit the protection myself on 19-inch rims with a very low-profile tyre?
Self-fitting is technically possible but not recommended on low-profile tyres (35/40): the tyre is difficult to partially break away from the rim without a machine. The approved fitter network carries out the fitting in approximately 1 hour, with an all-in cost for the fitted set of around €99 — eliminating any risk of damaging the tyre or rim during the process.
How do I know whether my rim diameter is compatible before ordering?
The AlloyGator online configurator lets you select your rim diameter and width to check compatibility and choose your profile colour. You can also browse directly to available accessories and sets by reference. If you have any doubt about an atypical rim (concave, extra-wide), an approved fitter from the network can confirm feasibility with no obligation.
Further reading
- 21 and 22-inch wheels: the risks of going very large
- 19 and 20-inch wheels: the real risk of low-profile tyres
- 17 and 18-inch rims: the most common diameters, and no less at risk
- 16-inch wheels: entry-level alloys deserve protection too
Further reading
