If you are new to over-landing/off-roading and you may want to begin building your perfect rig. The first place I like to start is with tires, and this can lead to some confusion. Tires come in two basic classes, P-passenger tires and LT-light truck tires. Contrary to the names given the tires the vast majority of new trucks and SUV vehicles in the US are sold with P rate tires. I am hoping to write this article to help explain to you how to pick a better set of tires for you rig.
Going back to when we used Bias Ply tires the weight rating system for tire capacity is bases on a letter/number scale: A, B, C, D, E etc. Each letter is 2 ply, so a B tire is a 4 ply, C is 6 ply, E is 10 ply. As a tire goes up in ply rating it can hold more air pressure and carry more weight. P rated tires are considered B rated tires. LT tires begin at C and run up beyond E. Radial tires do not actually add more layers or ply as they did years ago, but construction of the tires can be critical. LT tires are usually made with a more robust sidewall and tread to handle the extra air and weight. This robust construction can be critical in a hauling / off-road rig.
If you look at a standard P class tire and compare it to a LT C rated tire you may notice that the weight carrying ability is close or the same. Tire Manufactures apply a 10% rule with P rate tires on a truck, van, or SUV, which means the P rated tire has to be reduced by 10% in weight carrying ability. So the actual numbers can be deceiving. The reason for this is that trucks tend to carry the majority of their weight in cargo over the rear axle, have a higher center of gravity, and tend to get overloaded more. Passenger cars tend to distribute their weight more evenly over the front and back. Be sure to take this into account if you are looking at tires.
What are the advantages of replacing your tires with a Light Truck grade tire for over-land travel? You will be taking a lot of gear and supplies with you, the weight of all this material will be easier on a LT tire on a long distance travel. It’s better to have an LT tire carrying 80% of its max capacity than a P tire working at 100%. The harder a tire has to work the hotter it will get, this can cause a tire to literally come apart. Another good reason for an LT tire is because of its more robust construction it will be better able to withstand punctures and tears while off-road, and will better handle being aired down for extended off-road trips.
To give an example of this off-road ability I was running a Cooper AT C rated Lt tire, my hunting partner was running a Mastercraft (Cooper made) AT P rated tire. Over a 3 month hunting and trapping season we ran the same logging, fire, and back roads. He had to plug his tires 3 times that season, while I experienced not one issue. He now runs LT tires.
But, there are drawbacks to changing to an LT tire. Robust means more weight. More weight means your engine and transmission will work harder to move the tire, brakes will work harder to stop, and your steering will work harder to move them back and forth. Things will wear out faster. Expect a drop, though slight, in fuel mileage. And, that robust tire will be rougher in ride on the road and off. It will not flex and cushion as much which can stress suspensions and passengers a bit more.
I recommend that if you are trying to choose get on a sites like this and talk to folk who have the same rig, or tire you want to run. Get their advice and opinions. Research your tire brand and look at customer reviews. Also, you will need to deal with a tire shop that will try to tell you that you don’t need a- this grade or that rating. Find a tire shop that deals more in 4x4 off-road vehicles. Do your research and choose wisely for yourself. Good luck, see you on the trail.
Going back to when we used Bias Ply tires the weight rating system for tire capacity is bases on a letter/number scale: A, B, C, D, E etc. Each letter is 2 ply, so a B tire is a 4 ply, C is 6 ply, E is 10 ply. As a tire goes up in ply rating it can hold more air pressure and carry more weight. P rated tires are considered B rated tires. LT tires begin at C and run up beyond E. Radial tires do not actually add more layers or ply as they did years ago, but construction of the tires can be critical. LT tires are usually made with a more robust sidewall and tread to handle the extra air and weight. This robust construction can be critical in a hauling / off-road rig.
If you look at a standard P class tire and compare it to a LT C rated tire you may notice that the weight carrying ability is close or the same. Tire Manufactures apply a 10% rule with P rate tires on a truck, van, or SUV, which means the P rated tire has to be reduced by 10% in weight carrying ability. So the actual numbers can be deceiving. The reason for this is that trucks tend to carry the majority of their weight in cargo over the rear axle, have a higher center of gravity, and tend to get overloaded more. Passenger cars tend to distribute their weight more evenly over the front and back. Be sure to take this into account if you are looking at tires.
What are the advantages of replacing your tires with a Light Truck grade tire for over-land travel? You will be taking a lot of gear and supplies with you, the weight of all this material will be easier on a LT tire on a long distance travel. It’s better to have an LT tire carrying 80% of its max capacity than a P tire working at 100%. The harder a tire has to work the hotter it will get, this can cause a tire to literally come apart. Another good reason for an LT tire is because of its more robust construction it will be better able to withstand punctures and tears while off-road, and will better handle being aired down for extended off-road trips.
To give an example of this off-road ability I was running a Cooper AT C rated Lt tire, my hunting partner was running a Mastercraft (Cooper made) AT P rated tire. Over a 3 month hunting and trapping season we ran the same logging, fire, and back roads. He had to plug his tires 3 times that season, while I experienced not one issue. He now runs LT tires.
But, there are drawbacks to changing to an LT tire. Robust means more weight. More weight means your engine and transmission will work harder to move the tire, brakes will work harder to stop, and your steering will work harder to move them back and forth. Things will wear out faster. Expect a drop, though slight, in fuel mileage. And, that robust tire will be rougher in ride on the road and off. It will not flex and cushion as much which can stress suspensions and passengers a bit more.
I recommend that if you are trying to choose get on a sites like this and talk to folk who have the same rig, or tire you want to run. Get their advice and opinions. Research your tire brand and look at customer reviews. Also, you will need to deal with a tire shop that will try to tell you that you don’t need a- this grade or that rating. Find a tire shop that deals more in 4x4 off-road vehicles. Do your research and choose wisely for yourself. Good luck, see you on the trail.
