ZeDefender wrote:

Who would have thought a thread could go so terribly wrong - so tempted to quote that Wiki entry

At least there are no images

l

I can get you a picture if you like.

ZeDefender wrote:

I find mixing CO2 and Sulphurhexafluride grows cracking veg in the old polytunnel

twopoint6khz wrote:

Errrr, what's this about nitrogen getting less hot in a tyre than air? I don't see any way that can be true. Surely the vast majority of friction in a tyre is not within the gas itself, but as a result of the tyre rotating against the tarmac.

Quote:

Fundamentally; air, oxygen and nitrogen will all behave exactly the same in terms of pressure change for each 10 degrees of temperature change. However temperature alone is not the whole story.

Ambient air contains moisture, nitrogen does not. If moisture is present it contributes to a greater change in pressure simply because at lower temperatures water condenses to become a liquid. The liquid form of water occupies very little volume and contributes only a negligible pressure to the tire. But at higher temperatures, such as those in a running tire, water evaporates inside the tire and becomes a gas which increases pressure in the tire.

Ambient air contains about 21% oxygen. Oxygen’s smaller molecular size allows it to permeate through the rubber of the tire. By inflating with nitrogen, which is much less permeable than oxygen, the pressure changes due to oxygen loss are greatly reduced.

The racing industry is correct; nitrogen is more predictable. Because nitrogen is dry it has no moisture to contribute extra pressure changes with temperature. Because nitrogen permeates out much slower than oxygen pressure changes due to that leakage are almost eliminated compared with ambient air.

Basically if you have the ability to put nitrogen in then yes it is a good idea (or just put an air drier on your compressor).... but on a Land Rover I don't see the benefit. It isn't like you throw it around back roads at high speed to create huge amounts of heat. Nitrogen gets used in hgigh temperature aplications such as race cars, performance cars and aircraft.

Glyn