Quick answer: for a Porsche 992 GT3 RS, the BBS RT88 is the current vehicle-specific BBS Motorsport alternative in this comparison, while Porsche’s optional forged magnesium wheels remain the factory choice if minimum mass is the priority. The BBS E89 is a different proposition: late-model GT3 RS E89 setups are bespoke motorsport conversions rather than a current direct bolt-on BBS application, and brake clearance can require modification depending on the exact build.
Last updated: August 2026. RT88 specifications are checked against the current BBS Motorsport application list; OEM wheel and brake information is based on Porsche’s published 992 GT3 RS technical data.
Porsche 992 GT3 RS wheel basics
The 992 GT3 RS uses centerlock wheels and, from the factory, a staggered 20-inch front / 21-inch rear layout. Porsche specifies 275/35 ZR20 tires at the front and 335/30 ZR21 at the rear. The car can be equipped with its standard forged light-alloy centerlock wheels or optional forged magnesium wheels when specified with the Weissach package.
Porsche states that the optional magnesium wheel set saves approximately 8 kg in total compared with the standard forged wheel set. That makes the factory magnesium option the clearest choice when weight reduction alone is the objective.
BBS RT88 for Porsche 992 GT3 RS
The RT88 is the most direct BBS Motorsport option here because BBS publishes a dedicated 992 GT3 RS application. The current references are:
- RT88-060: 10 × 20 ET45, centerlock
- RT88-061: 13 × 21 ET31, centerlock
The RT88 itself is a two-piece forged wheel with an E88-derived forged center and the original forged BBS Japan LM rim. That construction gives it a very different appearance from the Porsche OEM wheel while retaining a dedicated, vehicle-specific centerlock specification.
See the BBS RT88 Centerlock for Porsche 992 GT3 RS for current pricing and availability.
BBS E89 on the 992 GT3 RS
The E89 is a genuine BBS Motorsport design, but it should not be presented as a simple current-production bolt-on alternative to the RT88 for the 992 GT3 RS. Known E89 installations on modern Porsche GT cars are custom motorsport configurations, and brake clearance depends on the exact E89 face, barrel, wheel dimensions and brake package.
There are documented late-model Porsche applications where E89 wheels required machining or a change to a different brake package to achieve clearance. For that reason, BaanVelgen treats a 992 GT3 RS E89 setup as a bespoke project that must be measured and verified, not as an off-the-shelf replacement for the OEM centerlock wheel.
This also means that broad statements such as “E89 is more comfortable than RT88” or “all E89s clear OEM GT3 RS brakes” are not useful. The engineering question is fitment: exact wheel construction, brake clearance, tire dimensions and intended use have to be defined first.
image courtesy of Glory Pursuit
Porsche OEM forged magnesium wheels
Porsche’s optional magnesium wheels are the factory lightweight benchmark. They retain the OEM dimensions, brake-clearance engineering and centerlock system, while Porsche states that the magnesium set saves around 8 kg compared with the standard forged wheels.
The advantage is clear: no custom fitment work and the lowest manufacturer-quoted wheel-set mass of the options discussed here. The trade-off is not a simple question of “fragility”; it is primarily cost, replacement cost, finish care and the fact that the visual result remains the factory Porsche design.
RT88 vs E89 vs OEM magnesium: side-by-side
| Wheel | Construction / status | 992 GT3 RS fitment | Brake compatibility | Main reason to choose it |
|---|---|---|---|---|
| BBS RT88 | Two-piece forged BBS Motorsport wheel | Dedicated current BBS application: 10×20 ET45 / 13×21 ET31, CL | Vehicle-specific application; final vehicle/brake spec still verified before order | BBS Motorsport engineering with E88/LM visual heritage |
| BBS E89 | BBS Motorsport wheel; bespoke late-GT conversions | Not treated as a current off-the-shelf 992 GT3 RS application | Can require machining or brake changes depending on configuration | Period motorsport aesthetic and custom motorsport build |
| Porsche OEM magnesium | Factory forged magnesium option | OEM 20/21-inch centerlock package | Factory engineered for the car | Lowest factory-quoted mass; Porsche states ~8 kg set saving |
Which wheel would we choose?
If the goal is the lightest factory-engineered solution, the OEM magnesium set is difficult to argue against. Porsche designed it for the car and publishes a meaningful total weight saving.
If the goal is a different wheel with a real BBS Motorsport connection, while keeping a dedicated current 992 GT3 RS specification, we would choose the RT88. It gives the car a completely different visual character without turning the project into a custom E89 brake-clearance exercise.
We would only choose the E89 if the customer specifically wants that wheel and accepts that the configuration becomes a bespoke motorsport project. In that case, brake package, wheel build and intended road/track use must be treated as part of the same engineering decision.
FAQ
What size BBS RT88 fits the Porsche 992 GT3 RS?
BBS lists RT88-060-BKBD in 10 × 20 ET45 and RT88-061-BKBD in 13 × 21 ET31, both centerlock and marked Overseas Edition.
How much weight do Porsche magnesium wheels save?
Porsche states that the optional forged magnesium wheels save approximately 8 kg as a set compared with the standard forged wheels on the 992 GT3 RS.
Does a BBS E89 fit the 992 GT3 RS with standard brakes?
Do not assume it does. E89 fitment on late Porsche GT cars is configuration-dependent, and documented builds have required machining or alternative brake hardware. A 992 GT3 RS E89 setup should be measured and engineered as a bespoke installation.
Is the RT88 a monoblock wheel?
No. It is a two-piece forged wheel using an E88-derived forged center and a forged BBS Japan LM rim.
Need help choosing?
See our BBS RT88 Ultimate Guide and RT88 Fitment Guide, or contact BaanVelgen with your 992 GT3 RS brake specification, current wheels and intended use. We can advise on the correct BBS Motorsport route before parts are ordered.
