Tyres with run-flat properties, known as SST (self-supporting tyres), offer extra safety and convenience. Even when deflated, the self-supporting tyres continue to run on the reinforced tyre sidewall at a top speed of 50mph for up to 125 miles. For safety reasons a tyre monitor display is always part of the package, because under normal driving conditions you may not notice that a tyre has deflated. This could lead to dangerous situations when cornering or under heavy braking.