I saw this thread earlier but cant post this comment as i can't find the original thread [for which i would be greatfull if somebody does find it they could move this thread to that area.. The reason why Nitrogen is so good for your tyre fill is because its boiling point is -195. This means that the tyre retains its heat better and helps your tyre warm up. Those who are GP1 fans will know what i mean when they see the cars on the warm up lap swerving from side to side. Warm tyres give your car [in the absence of winter tyres something ex BOAR troopies will be familer with] that extra grip on the road in winter conditions. Which is why in the UK you find your self behind wankers and tossers driving really slowly so that they don't skid, when in fact they should be driving at some speed to get some warmth into their tyres. Winter Tyres are made of a softer compound which has the same effect as adding nitrogen to the tyre.