Quote:
Originally Posted by RedDevil
Like I promised I tested the air in my tires.
The fact that the rate of pressure decline went down noticeably over time also confirms that nitrogen does in fact seep out less easily.
I did not expect that.
Myth confirmed, I guess.
So, apparently there is a benefit from filling tires with "nitrogen enriched" (oxygen depleted) air. They will keep their pressure better than tires filled with plain air, as those will lose most of their oxygen.
Having said that, you will need to keep an eye on the tire pressure regularly regardless of what they are filled up with, and in the end you will end up with almost pure nitrogen anyway.
You will just need slightly more air than if you use pure nitrogen.
As for better ride quality etc; obviously even if it does make a difference it is hardly an issue as the oxygen will get lost anyway.
|
Hah, nice testing! I didn't think it'd work quite that well, impressive. One could over inflate the tires for awhile I suppose increased psi would force the O2 out that much faster.
I wasn't under the impression though that the benefits of nitrogen filled tires are myths, they are well known, if minimal or irrelevant to most street driven vehicles on an individual basis anyway. And clearly, the only actual FE benefit is for the less OCD among us. (ok lazy). I really have no idea why this is in the unicorn corral.
I get that individually N2 is of marginal benefit. To an individual with a fastidious personality - I think we can safely say no benefit. However, taken en masse, if every tire on earth were filled with N2 tomorrow, the effects would be profound.
Quote:
An estimated 93.5% of motorists in the EU are driving on under-inflated tires and causing an additional 18.4 million tons of carbon dioxide to be released into the environment, according to a recent analysis by Bridgestone Europe. That works out to an extra 6.9 g CO2/km for every car on Europe’s roads.
Based on the data collected in 2006, Bridgestone also estimates that 40% of vehicles consume an additional 2.8% in fuel due to their under-inflated tires, wasting 8.1 billion liters (2.14 billion gallons US) of fuel every year.
To collect data for the study, Bridgestone conducted free safety checks on 20,300 passenger cars in 19 EU countries during 2006. Only 6.5% of motorists had all tires correctly inflated, 54% had some degree of low inflation and 39.5% had at least one tire significantly under inflated (<1.5 bar or 21.8 psi). 12.0% of cars (1 in 8) were in danger of tire failure.
The free check-ups were conducted by Bridgestone at shopping centres and public car parks. They form part of the “Think Before You Drive” safety education campaign, a worldwide joint initiative between the FIA Foundation (Fédération Internationale de l’Automobile), Bridgestone Corporation and national motoring clubs, launched in 2005.
These results suggest that many motorists are unaware that a tire loses pressure naturally over time, like a balloon, and that driving on incorrect pressure can be dangerous. The loss of handling control and increase in vehicle drift rises sharply as tire pressure is reduced. Low tire pressure also has an extremely negative effect on tire durability, due to excessive shear stress in the shoulder and heat build-up from sidewall bending. The 12% of motorists identified with seriously low tire pressure face possible tire failure due to these factors.
The wear life of a passenger car tire is halved if pressure falls from 2.2 bars (32 psi) to 1.0 bar (14.5 psi). Based on this 2006 survey, Bridgestone’s Technical Centre Europe calculates that the almost 40% of motorists at risk are losing 19.3% of tire wear life—an average of 9,700 km or 9 months of tire usage (based on an average wear life of 50,000 km and annual mileage of 13,600 km).
A further 54% of vehicles are losing 5.2% of tire wear life; an average of 2,500 km or 2 months of tire usage. Adding these two groups together shows that 24.5% of tire wear is being lost through under-inflation in Europe.
Inflation pressure has a strong influence on tire rolling resistance, which is itself a key factor in determining vehicle fuel consumption. Depending on the type of road and driving style, rolling resistance represents 18% to 26% of the total force on a vehicle. Since low inflation increases rolling resistance, it has a direct effect on vehicle fuel efficiency and emissions.
|
So, seriously, unicorn corral? If every auto manufacturer started filling tires with N2 tomorrow, imagine how much fuel that would save over the years, how much tire wear it would reduce, and how much safer people would be. Less blowouts, for example.
All that benefit just from the simple fact that N2 molecules are bigger than O2 and leak out slower.
Another note, is the Ferrari tire gas incident with McLaren in 07. McLaren stole Ferrari's super secret tire gas formula and according to Ferrari the gas made a huge difference in tire performance. The gas was basically half r404 refrigerant and half CO2 and I guess it helped transfer heat from/to the tire>air>wheel where the wheel performed somewhat as a radiator.
I'm totally unfamiliar with how a tire actually wears and why. Does the amount of heat generated by normal highway or city driving affect how fast the tire wears to any significant degree? If it did, a tire gas that transferred heat from the tire to the wheel might have some benefit for tire longevity over the years. Say getting 55k miles instead of 50k or something like that. Just a thought I had.