Tyres "perishing"

Ultrasonic

knightstyle wrote: »

Nitrogen in tyres is available in France for 1€ a tyre when you buy new tyres. Our friends have it as they are getting on and with nitrogen you do not need to check the tyre pressures, just go in once a year to the tyre place.

Not checking tyre pressures because they were filled with Nitrogen is a daft idea. Pressures will still vary with temperature, and nitrogen could perfectly easily still leak out of a less than perfet valve.

They have it in their caravan tyres as well and say that their mpg is better since having it.

I don't believe nitrogen in tyres will improve mpg in the slightest. Higher tyre pressures lead to reduced rolling resistance, so if nitrogen somehow magically doesn't increase in pressure with temperature the if anything this would reduce mpg, not increase it. But nitrogen isn't magic . Is it possible that when the tyres on the caravan were filled with nitrogen they were simply inflated to a higher pressure than before? That would improve mpg, although it would need to be a big pressure increase to be really noticeable.