Porsche has expanded a 2024 'do not drive' recall to cover an additional 548 of its highest-performance cars, because their center-lock wheels could fall off.

The new batch covers 2024 model year 911 variants — GTS (168 cars), Turbo S (94), Turbo (13), GT3 (50), GT3 RS (41) and S/T (39) — plus 73 718 Cayman GT4 RS and 70 718 Spyder RS models.

Porsche says owners should not drive these cars until a dealer has checked the center-lock wheel fastening system and replaced any out-of-specification parts.

The original recall, issued October 28, 2024, covered 1,851 2024 911 Turbos and 718 GT4 RS and Spyder RS models, bringing the total now to 2,399 cars in the US.

The affected wheels are a signature enthusiast feature: racing-style center-lock hubs secured by a single large nut rather than the four or more lug nuts on a conventional wheel.

According to Torque Cafe, Porsche's Australian recall notice warned that 'the road wheel centre-lock nuts may fracture,' which 'could cause the wheel to loosen and detach from the vehicle whilst driving,' risking a loss of stability and control.

The cause, per the NHTSA recall report, is a supplier defect: analyses of the affected material batch confirmed lead and bismuth contents outside specification, and center-lock components in certain production ranges were manufactured out of specification.

Yahoo Autos reports that the latest 'do not drive' warning arose after two additional field accidents involving fractured center lock components earlier this year, in May and August, though no injuries were reported.

Porsche says it is aware of several incidents attributable to center lock fractures and notes that owners should feel immediate vibration if a center lock fractures, so a driver whose 2024 Porsche suddenly starts vibrating should pull over as soon as possible.

Notably, 100% of the cars in the first recall were estimated to be affected by the fault, while just 1.4% of the cars in the new batch are expected to be.

Repairs will cost owners nothing, since all affected cars are still covered under their warranty, and Australian owners will also have work done free of charge at an authorised Porsche Centre, Torque Cafe reports.

US owners will be contacted by phone, email and MyPorsche App push notifications by December 15, and vehicle identification numbers are already searchable on NHTSA's website.

With roughly 2,400 cars affected in the US alone and no figure yet announced for other markets, the recall spans a global community of GT3, GT4 RS and Turbo owners whose cars are effectively undrivable until checked.