Tire Load Index; Interesting

[acadianbob]

So, the Goodyear Wrangler LT AT/S Load Range C has a Load Index of 113 or 2535 lbs per tire at 50 PSI. (275/65/18)

The Nokian Vatiiva on my current truck (265/70/18) (a P metric tire) has a Load Index of 116 or 2756 lbs per tire at 44 PSI

This goes back to some previous discussion about LT vs P tires. It doesn't seem to be automatic that LT tires have more capacity. At least not LR C. It apparently takes LR E to have any real capacity benefit.

[donn]

Over the years the nomenclature seems to have changed. Back when I was in the business and the letter designations were first introduced all they meant was:
P= Passenger
LT= Light Truck
Beyond that there has always been a load rating listed for each tire within the general designation. What I think has happened is too many people forgot the original indications and now assume that just because the tire is marked LT it will carry as much weight as they want to load on.
With the blurring in the light truck market today it is becoming exceedingly difficult to determine what is really a light truck and what is a passenger car with an open bed in back.

[sreddy]

The following seems to cover the difference:
Tire Tech Information - Load Reduction of Euro- and P-Metric Tires on Light Trucks
"However there is an idiosyncrasy governing the use of Euro-metric and P-metric sized tires on vans, pickup trucks and SUVs because these vehicles have a higher center of gravity and greater probability of being overloaded than passenger cars. In order to accommodate this, vehicle engineers are required to specify Euro- or P-metric sized tires rated to carry 10% more weight than would be required if they were used on a passenger car. This is the equivalent of taking the tire's load capacity branded on its sidewall and multiplying it by 91%. For example, a Euro- or P-metric tire designated to carry 2,000 pounds on a car is restricted to carrying 1,820 pounds when used on a van, pickup truck or SUV. This size selection practice provides the vehicle manufacturer with the appropriate tire load capacity."
.
So the Nokian on a light truck application is safe to 2507# per the article

[acadianbob]

Originally Posted by sreddy

"However there is an idiosyncrasy governing the use of Euro-metric and P-metric sized tires on vans, pickup trucks and SUVs because these vehicles have a higher center of gravity and greater probability of being overloaded than passenger cars. In order to accommodate this, vehicle engineers are required to specify Euro- or P-metric sized tires rated to carry 10% more weight than would be required if they were used on a passenger car. This is the equivalent of taking the tire's load capacity branded on its sidewall and multiplying it by 91%.
.
So the Nokian on a light truck application is safe to 2507# per the article

Very interesting! I had never come across this information. And this is a good source too. Thanks.