Yhe advantages of using Nitrogen in inflating your tires:
(Posted by Beebs at the Fortuner Forum)

Why use Nitrogen
· Nitrogen is an inert gas that has a larger molecular structure than Oxygen.
· Safety
· Proper tire pressure maximizes a vehicles braking and steering capability
· Elimination of oxygen results in fewer internal tire failures
· Reduced chemical aging reduces the risk of tire failure
Tire Performance
· Proper tire pressure optimizes a vehicles handling
· Proper tire pressure improves ride quality
· Economy
· Proper tire pressure minimizes rolling resistance, leading to better fuel mileage
· Proper inflation pressure optimizes tire life
Features & Benefits
· Does not diffuse as easily: nitrogen molecules are larger than oxygen, which means that it has a slower rate of pressure loss.
· Nitrogen permeates the tire at a rate of 30-40% slower than oxygen
· Inert gas: nitrogen disperses heat more quickly which results in cooler running tires
· Improved tread life
· Reduced incidences of tire damage caused by excessive heat
· Non-flammable; reduced chance of flash point explosion
· Potential for better fuel mileage; if heat is restrained from building up the rolling resistance is reduced which can improve the vehicles fuel economy
· Reduced pressure build up: maintaining pressure reduces the deflection, which again prevents heat build-up and reduces the chance of separation
· Over-pressurization is as problematic as under-pressurization
· Increased tire pressure above the recommended inflation point can reduce the contact patch and thus reduce the maximum possible grip levels.
· Reduced moisture content introduced to the tire
· Nitrogen is dry because of it's inert qualities. Many of the causes of failure in a tire can be attributed to moist air being introduced internally to the tire.
· Moisture causes rusting, especially of the stem valve, increasing leakage. Additionally heating in tires is often caused by vaporization of the moisture
Who Uses Nitrogen Today?
· Aircraft tires
· Used for consistent pressure and minimized oxidation of rubber compounds
· NASCAR & Fomular 1
· For improved, consistent handling and reduced operating temperatures
· Heavy contruction equipment
· For consistent tire pressure and to prevent auto-ignition
· US Goverment / military equipment
· NASA - space shuttle