Tires- LT or ST

Huntindog wrote:

StirCrazy wrote:

Huntindog wrote:

The fact is that the govt. LT tire testing standards are much more demanding than for ST tires. That being a FACT, it is not hard to understand why STs fail so often.
On another note: LT tire choices in the 16" rim size are many. In fact most if not all manufacturers offer Good, Better, Best models to choose from. Such selection just isn't availible in ST tires. There is a choice of ONE from each manufacturer...So if one wishes to buy a premium ST tire,,,There are none availible....But as an observation of the testing standards, the cheapest LT tire is tested to higher standards than any ST tire.

didn't we have a thread a while ago where we found that the testing standard for both tires is virtually the same, but the LT does one test to a higher speed (partially loaded I believe it was at 60PSI) where the ST does a higher max load test? doesn't sound like it is much more demanding, or a fact.

This is the part you missed: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.

And here is the part you missed: ST tires are rated for about 20% more load than LT tires. The net effect is the tires are tested at the same load - more or less.

So when installed on a trailer, the load is the same regardless of which type of tire you put on.