Nitrogen molecules are bigger than oxygen molecules they do not pass through the microscopic pores present in the tyre walls, thus maintaining them at the right pressure for periods 3-4 times longer. Given that nitrogen does not contain oxygen it does not oxidise the metal rims of the tyres or the metal valves and for the same reason is not inflammable. These characteristics mean that a tyre filled with nitrogen maintains the tyre pressure at an optimal level, saving money and offering both greater comfort and safety to passengers. The main benefits of constant, optimum tyre pressure are: - Reduced fuel consumption - Improved grip - Reduced braking time - Prevention of blow-outs - Reduced wear on the tyre- longer average life - Elimination of damage caused by oxidation - Reduced stress to the car chassis.At Zentrum we can fill your tyres with nitrogen for ONLY £20 per car