Tires: Extra Load tires, tire placard, worldwide practice

Question
I am trying to decide which tires to purchase for my truck. I have a 2001 Dodge 1500 club cab 2wd. I pull a 12' stock trailer weighs 2150 lbs with a horse weighing 1400-1500 lbs. Tires on it now are 255/70/16. I would like a tire that handles well with the extra load, is quiet, not real expensive that can handle long trips pulling the trailer and horse.Should I be going to a 10 ply or what? I am really confused. I would like to know the specific tires of which I should choose from. Please

Answer
Tam,

Let's start with  the basics:

On every vehicle sold in the US - and I understand this is a worldwide practice as well - there is a sticker – commonly called the vehicle tire placard - that lists the original tire size and the proper pressure for that size.  The placard is usually located on a doorpost or in the glove box – but sometimes it is located in the trunk or on the fuel filler door.

BTW, it doesn't matter who makes the tire or what pressure is listed on the tire's sidewall, if the tire size is the same as the placard, then the pressure listed on placard is also appropriate.

One word of caution:  Some trucks use tires with the letters "LT" in front of the tire size - and some trucks use tires with the letter "P" in front of the tire size - and some trucks use tires with the letter "C" after the tire size.  You should not use "P"'s in place of "LT"'s and vice versa.

For this situation, you should be sure the pressure on the sidewall equals or exceeds that pressure on the placard.  If you do this the issue about the letter "C" in the sidewall will take care of itself (which is not true with "LT"'s vs "P"'s.)

If you are using a tire size that is different than what is listed on the placard, then the pressure has to be recalculated.  The calculation is not difficult, but it requires tire load tables which are not allowed to be published in the Internet because of copyright laws.  However, I have a copy and would be glad to do the calculation, but the starting point is the vehicle placard: Tire size and inflation pressure.  I will also need to know the new tire size.

The second thing you need to do is be sure you are towing within the limitations of the vehicle.  You need to look at your owners manual or call the vehicle manufacturer.  The key items are trailer weight and tongue weight.

If you are towing within the capability of the truck, then the tire size listed on the vehicle tire placard is adequate.

Now you mentioned 10 ply and those would be LT type tires - and I discussed that above.

But aside from that, you have to decide what else you want the tire to do.  Will a straight street pattern work or do you need an all terrain?  Is wear more important than fuel economy?

Once you have done that, you can now shop.  Try Tire Rack and their "Tire Decision Guide".  That should help narrow this down for you.