Ask for tire based on the Load Index (which correlates directly to the load rating).
The ABCD... is an old system based on how many nylon plies the tire is made from...except no one has made 10 ply tires for for pickups in years. With modern steel belted tires, they give you a rough approximation of the ply equivalent but the actual load rating will vary a surprising amount within the same ply rating. You don't really care about plies. You want to know the load rating (I'm a bit baffled why they went to Load Index rather than just listing the load rating but it's the more easily searched figure).
Look at the sticker on the door and calculate the minimum load rating for the tires based on the max axle rating:
- You should do if for both axles and pick the higher resulting per tire load.
- I would generally go a little higher on the rating but not drastically.
- I would also go with an LT tire over a P rated tire.
Honestly, better to research online and go in with the specific model and price.
