Run Flat Tires: General Overview
Run flat tires are factory equipment on many BMW, Mini, and some other models. Here is a general overview of how they work and typical trade offs.
Run flat tires use reinforced sidewalls that can briefly support the weight of the vehicle even with very low or zero tire pressure. The typical design allows limited additional driving distance at reduced speed after a puncture. Specific limits are set by the tire manufacturer.
Commonly Cited Benefits
- No spare tire is typically required, which frees up trunk space.
- Reduced risk of a sudden pressure loss causing loss of control at highway speed.
- Ability to drive a limited distance to a service location.
Commonly Cited Trade Offs
- Stiffer sidewalls can result in a firmer ride compared with standard tires.
- Higher unit cost compared with standard equivalents.
- Repair options are more limited and are governed by the tire manufacturer policy.
- Fewer sizes and fewer winter options in some markets.
Switching to Standard Tires
Some owners choose to replace factory run flats with standard tires. When doing so, carrying an inflator kit or roadside assistance is typically recommended since most vehicles originally equipped with run flats do not have a spare. The TPMS system will continue to function with standard tires. Do not mix run flat and non run flat tires on the same axle.
Always confirm suitability, load rating, and speed rating with a qualified tire professional and review the vehicle owner manual.