[rhagfo]

Originally Posted by Javi

So, what happened... I asked a fair question, especially amid the discussion and proselytizing on LT tires and their miraculous lack of deterioration, built in safety margins concerning load capacities, life expectancies, etc.

I am an engineer, I need more than... I researched it, I believe, I personally ran... etc. I need proof, documentation, results which can be quantified..

I repeat...

So, you're assuming or maybe advocating that LT tires don't degrade at all or at some much reduced rate than do ST tires...

I'd like to see documentation on that and on the much touted "SAFETY MARGIN" built into the LT tire..

It is my consideration that any mandated safety margin would most likely be in fitment, rather than in the tire capacity rating..

Can you show documentation to the contrary?

So far I have not seen irrefutable evidence to support the assertion that I break the law/rules or policies in the tire industry by mounting tires which have less load capacity than the O.E.M. fitment...


I'm waiting...

I have included sections of this post below.

http://forums.goodsamclub.com/index....g/1/page/1.cfm

The testing for (3) endurance was found to be significantly different between the ST and LT tires.

Both the ST and LT are put through the same initial pressure, time and load profile. The total profile lasts 34 hours of continuous run time starting at 85% of rated load and ending at 100% of rated load. To further stress the tires, a load range E tire (nominal 80 psi rating) is tested at a reduced pressure of 60 psi to induce additional load on the tire during testing. (This is reasonable that testing should be conservative.)

But now the endurance testing diverges significantly.

The ST tire is tested at this pressure, time and load profile at 50 mph. After that, the ST test is over.

The LT tire is tested at this pressure, time and load profile at 75 mph. This is a 50% increase over the ST and will induce significant additional load and heating on the tire during testing. After that, the LT test is not complete. Next a “Low Inflation Pressure Performance” test is performed for the LT tire only. The tire pressure is decreased to 46 psi and the tire is immediately run for an additional 2 hours at 75 mph and 100% of rated load.

Thus, the LT tire endurance test is drastically more intense than the ST endurance test.

The testing for (4) high speed performance.

The difference in high speed performance testing between a ST and LT tire is significant. Both tires are tested through a 90 minute speed/time profile.

The ST tire is tested 88% of rated load while the LT tire is tested at 85% of rated load. Thus, the loading is 3% higher based on rated load and this slight advantage goes to the ST tire.

However, the LT tire is tested at significantly higher velocities when compared to a ST tire (99 vs. 85 mph maximum speed). This is a 16% advantage to the LT tire.

Thus, again the overall test for the LT is more rigorous than the ST test.