Can run-flat tires still be driven when deflated?
4 Answers
Run-flat tires can still be driven when deflated, allowing continued driving at speeds up to 80 kilometers per hour without immediate tire replacement. Run-flat tires feature thickened rubber sidewalls that can support the vehicle's weight even when air pressure is lost, preventing severe deformation. Therefore, a punctured run-flat tire won't significantly affect the vehicle's operation. These tires consist of an outer tire, standard inner tube, spare inner tube, steel rim, gas generator, pressure sensor, and control unit. The rims are specially designed with raised ridges to prevent tire separation from the rim after sudden pressure loss, ensuring the tire doesn't detach when deformed.
Last time on the highway, my run-flat tire suddenly triggered a warning, and my palms were sweaty. These tires have reinforced rubber layers on the sidewalls to support the vehicle even when completely flat, allowing me to cautiously drive for 20 minutes to reach a repair shop. But remember to keep speed under 80km/h, or the wheel rim may deform, making repairs more expensive. My BMW can last up to 80km in this condition, while a Mercedes might manage around 50km. The steering wheel becomes extremely heavy, and the car noticeably leans toward the deflated side. In such situations, avoid sudden braking—turn on hazard lights and slowly coast to the emergency lane for safety.
Can you drive on a flat run-flat tire? Don't be fooled by the name! My personal experience with my MINI showed that while the car could move after a puncture, the rim was hitting the ground with loud bangs. The tire could last at most 80km before being completely ruined. The mechanic warned that prolonged driving with low pressure could deform the wheel rim. Nowadays, when the tire pressure warning light comes on, I slowly drive to the nearest repair shop, but if it's more than three kilometers away, I call a tow truck instead. Oh, and remember to get wheel balancing done when patching the tire, otherwise, the steering wheel will shake alarmingly at high speeds.
Personal experience: Drove 15 kilometers at 60 mph with a nail in a run-flat tire. This type of tire has three life-saving designs: 1) The sidewall is thickened by 50% to support the vehicle's weight, 2) A special rubber compound resists high temperatures, and 3) The wheel rim has a flange to prevent detachment. However, three precautions must be noted: Do not exceed 80 mph, limit the distance to within 80 kilometers, and replace the tire if the damage exceeds 6mm. Once saw someone continue driving with a bulging tire sidewall, resulting in the tire tearing apart and the rim getting scratched, costing over 3,000 in repairs.
