DSST (Dunlop Self-Supporting Technology)
A run-flat is designed to resist the effects of deflation when punctured and to enable the vehicle to continue to be driven at reduced speeds for limited distances, depending on the type of tyre/ vehicle.
DSST stands for Dunlop Self Supporting Technology and when a vehicle is eqqipped with these tyres, no spare tyre is needed.
Under certain conditions DSST tyres will offer mobility for a maximum distance of up to 80km at a maximum permissible top speed of 80km/h with a total loss of air pressure. However, a careful, rather defensive driving style should be used. The vehicle manufactures’s instructuons must also be referred to, as these may contain deviations from the general restrictions for individual models and certain tyre combinations.
The three advantages of Run Flat type
The primary benefit of using run-flat tires is continued mobility in case of a loss of air pressure, either due to a ‘normal’ puncture or a hostile deliberate act or even a bullet shot while the vehicle is travelling at high speed. Performance criteria are therefore in terms of distance and speed at which the vehicle can escape without becoming immobile and the steering control over the vehicle during this process.
Not needing to carry a spare wheel: The space can be used for other purposes. Also, the absence of a spare wheel contributes to lower vehicle weight which will in turn reduce fuel consumption, reduce harmful exhaust emissions, improve performance, handling and braking characteristics. However, these may be negated by the increased weight of the tires if they are self-supporting.
Internal bracing in some run-flat tires reduces deformation, with the opposite effects of reducing rolling resistance and improving fuel efficiency