Nitrogen
Nitrogen In Tires... Its All The Rage!
What is Nitrogen?
Nitrogen is a dry, non combustible, inert gas making up 78%
of the air we breath. In the last 30+ years it has begun to find
its way into the tires of giant
off-highway earthmovers, aircraft and most every type of race car.
They main reasons are it improves
performance, increases tire mileage, offers better fuel economy and
extends the life of the tire's rubber and steel construction materials.
A few basic facts:
NHTSA RESEARCH....
Chemical aging is due to oxygen diffusing through the tire composite and
reacting with the internal components. If the rate at which air diffuses
through the tire is slowed, the rate of chemical aging will be similarly
slowed. (Review the FMVSS 139 for additional information on mechanical
aging effects.)
AIR PERMEABILITY TEST PHILOSOPHY....
According to tire manufacturers: - tires with more expensive, 100%
halogenated-butyl inner liners lose air at a rate of 2.0-2.5% per month
(10 lbs per year @ 35 psi)- tires with cheaper, blended butyl inner liners
lose air at a rate 4.00-5.0% per month - for the same inner liner
compound, a thicker inner liner will lower the air loss rate - a reduction
in air loss rate, by a factor of 2, may be achievable for some tires.
NITROGEN TEST....
In on the road tests involving over 7
million miles of truck tires
inflated with nitrogen, tire failures were reduced by half and tread life
increased by 25% to 30%. The benefits were repeated in the second tire
life after re-treading. These mileage comparisons were followed by
electron microscope analysis which measured
oxygen levels in the tire body and tread of tires inflated with air and
then operated on the road until replaced because of failure or tread wear.
The results were conclusive; oxygen kills tires over time. Similar tests
on automobile tires yielded comparable increases in tire life. (Reference:
Million Mile Truck Tires – Available Today by Lawrence Sperberg.)
NITROGEN STUDY....
In a study reported in Rubber and Plastic News by David Coddington of
Exxon Chemical Co. material from tires run for varying periods of road
service and inflated with air was tested for tear strength. The laboratory
findings; strength values are steadily decreased with increasing service
mileage, leveling off at a value below 50% of original strength. In lab
testing equivalent to less than 40,000 road miles, the relative strength
of oxygen exposed tires declined to under 40% while the material from
tires inflated with nitrogen held at over 80%.
TIRE DURABILITY TESTING.....
Tire life to failure point in laboratory wheel tests confirmed more than
twice the life for the nitrogen inflated tires. (Reference: "Factors in
Tubeless Radial Tire Durability", Rubber and Plastic News, August 1993.)
GOODYEAR BULLETIN.....
Nitrogen inflation has advantages in that tires will hold pressure longer
using nitrogen. Nitrogen’s diffusion rate is 25% to 30% lower than air,
significantly reducing tire pressure loss between inflation checks. Under
inflated tires wear rate is increased to the point where a tire 10% under
inflated will lose approximately 7% of it service life. On the other hand,
properly inflated tires have less resistance to rolling. (References:
Goodyear Application Bulletin #17 and Bandag Tread Guide, September 1995.)
AAA (AMERICAN AUTOMOBILE ASSOCIATION)....
Under inflated tires can cut fuel economy by as much as 2% per pound of
pressure below the recommended level. Therefore a tire that is just five
pounds below its setting will consume 10% more fuel. Additionally, tires
with low air pressure are more sluggish in their response to steering
input... compromising your vehicle’s handling. |
Ever notice green valve stem caps on another cars tires? Those tires are filled with nitrogen!
Why use Nitrogen? |
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- Less inflation pressure loss
- Reduced wheel corrosion
- Prevents inner rubber deterioration by oxidation
- Tires run cooler
- Increases tread life
- Increases fuel mileage
- Helps prevent uneven wear
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