Originally Posted by OldCoot
Does buying an E-rated tire (instead of a C) give you a stronger, and thus safer, tire? It is the air pressure not the tire that carries the load so the answer is NO
Please explain the reasoning behind this.
How can that be? That implies that merely inflating a C to 65# would carry the load of an E rated tire. Makes no sense to me.
If an E rated tire is not stronger than a C at the same pressure, why are there different load rated tires?
It is the air pressure in the tire (balloon) that transmits the load from the road surface to the wheel.
The "strength" or Load Range of a tire is its ability to hold the pressure. Decades ago there were "ranges" established to replace the old term "Ply Rating" The more plys of cotton (ply material way back when) the more pressure the tire could hold. The more pressure in a tire the more load it can support. To avoid confusion, discrete increments were established so competing tire companies would not be claiming "my tire is stronger because it carries more at 62 than your tire does at 61psi.
A review of Load Inflation tables will show that a LR-C and LR-D and LR-E are rated to carry the same load when inflated to the same pressure.
I did a post on my blog Oct 15 just on this topic with s special pressure plot from a test lab showing that is is not the sidewalls that carry the load.
I write a blog on RV tire application and safety. RVTireSafety.com
Also give seminars on tires at RV events across the US. 40 years experience as tire design & quality engineer for major tire mfg. Freelander 23QB on Chevy chassis is my RV