Tires: P vs LT245/75/R16, tire failure, max pressure

Question
What is the difference.  I ordered Michelin LT245/75/R16  LTX
A/T2 as that was on my 4x4 Suburban and they mounted P245/75/R16.  I go off road on our farms.  Do I need to have them switched to the correct tire.

Answer
Debbie,
I do not recommend switching between P metric and LT metric.  You have the worst case:

Find your vehicle placard, it will be located on the doorpost.  Notice the pressure listed there.  It will probably say 50 psi or more - perhaps even 80 psi.

Now look at the tire.  It will either say max pressure 35 psi or 44 psi.  In other words, the vehicle manufacturer wants you to use more pressure than the tire is capable of.

Returning to the dealer you bought the tires from and point all this out to them.  Don't forget to mention that pressure = load carrying capacity and that using less pressure could result in a load related tire failure, which sometimes has tragic results, which they would be responsible for.