Tires: load range criteria, inflation pressure, road tires

Question
what,if any, are the legal criteria involved in putting load range d tires on a lifted truck in a bigger size than stock when original equipment was load range e? The bigger off road tires actually have greater load capacity than the smaller oe load range e tires

Answer
Jeff,

First, I am not an attorney, so I can only give you my understanding of the way this works.

Fundamentally, a replacement tire should have the same or more load carrying capacity as the original tire at the inflation pressure specified on the placard.  So it would be OK to put on a Load Range D, so long as the load carrying capacity at the usage inflation pressure was larger than the Load Range E tire was at the placard inflation pressure.

But there are a number of interesting problems here.  One is that with a lifted truck as well as a tire with a larger diameter, results in a vehicle center of gravity that is much higher than stock, and it makes the vehicle more prone to roll over.  The vehicle manufacturer would not be held liable because the vehicle is substantially modified from when it was manufactured, but whoever did the lift and / or applied the tires could be considered as "certifying" the vehicle and held liable for any resulting accident.