Run Flat Tyres Explained
Several Tyre Manufacturers have developed tyres, and tyre systems that allow a vehicle to continue moving despite a loss of pressure. There are two different approaches:
1. Reinforced Tyre Sidewall. Manufacturers that produce these include Continental, Dunlop, Goodyear, and Pirelli.
2. Rubber clip to your rim. Manufacturers that produce these include Michelin.
All Run flat technology must operate in tandem with tyre pressure warning systems.
1. Reinforced Tyre Sidewall
The diagram below shows the Dunlop DSST run flat system. These tyres can be placed on any rim - the sidewall is reinforced allowing the tyre to support the vehicle's weight. The tyre is constructed with new rubber compounds that prevent tyre destruction with excessive flexing. Run Flat Tyres allow a vehicle with complete loss of tyre pressure to handle effectively. Braking, acceleration, and steering behaviour remain unchanged. Mobility is also maintained even after a puncture, but you must refer to each individual tyre’s guidelines from the Manufacturer.
2. Rubber Clip to your tyre rim
The rubber clip prevents the tyre rim cutting into your tyre when you experience a sudden loss of pressure. This system has been developed by Michelin and is known as the PAX System. Like the reinforced sidewall it operates in tandem with automated tyre pressure monitors.
Why fill my tyres with Nitrogen?
Why would you want to do this? The benefits of Nitrogen filling are as follows:
- Improved comfort of ride
- Improved safety
- Increased fuel savings
- Improved life of tyre
Nitrogen has long been the accepted gas medium for filling aircraft tyres, racing tyres and heavy mining and construction vehicle tyres.
Nitrogen is used for safety reasons and to ensure that tyres are always at a constant pressure. Compressed air, the traditional medium for inflating car tyres, contains both oxygen (21%) and nitrogen (78%).
The rubber tyre is like a membrane, through which oxygen permeates three times faster than the nitrogen. The result is that the oxygen slowly leaks out through the rubber walls, and the under-inflation leads to higher tyre wear with a consequent decrease in safety and comfort, and higher fuel costs.