LT vs Passenger Tires for SUVs: Load and Ride

What Are P-Metric and LT Tires?

Tire size designations tell you a lot about a tire's intended use. A P-metric tire, such as P245/70R16, is a passenger car tire. According to Federal Motor Vehicle Safety Standard 571.139, a passenger car tire is intended for use on passenger cars, multipurpose passenger vehicles, and trucks with a gross vehicle weight rating (GVWR) of 10,000 pounds or less. An LT tire, such as LT245/70R16, is a light truck tire, defined in the same standard as a tire designated by its manufacturer as primarily intended for use on lightweight trucks or multipurpose passenger vehicles. Both can fit on many SUVs, but they are built with different priorities.

The distinction matters because your SUV's weight, towing, and payload demands determine which type is appropriate. If you only occasionally carry passengers and light cargo, a P-metric tire is often sufficient. If you frequently tow a trailer or carry a heavy load, an LT tire may be necessary to provide the extra load capacity you need. For a detailed explanation of tire size markings, see tire size explained.

Load Capacity and Inflation

Load capacity is a measure of the maximum weight a tire can carry at a given inflation pressure. Both P-metric and LT tires have load ratings printed on the sidewall, but LT tires are designed to operate at higher inflation pressures and, therefore, can support heavier loads. The Federal Motor Vehicle Safety Standard 571.139 defines load rating as the maximum load a tire is rated to carry for a given inflation pressure. LT tires are often available in higher load ranges, such as load range C, D, or E, which correspond to increasing strength and load limits.

When you install a passenger car tire on a multipurpose passenger vehicle, the effective load capacity can be lower. For vehicles with a GVWR over 10,000 pounds, Federal Motor Vehicle Safety Standard 571.120 requires that the tire's load rating be divided by 1.10 before comparing it to the axle rating. This derating recognizes the higher demands placed on tires used on trucks and SUVs. Even on lighter SUVs, you should check the vehicle's placard and the manufacturer's recommendations to ensure your tires meet the load requirements. For more on load ranges, see tire load range for light trucks.

Construction Differences and Sidewall Stiffness

The internal construction of LT tires differs from that of P-metric tires to handle the extra stress. While both are almost always radial ply, LT tires often use additional plies or reinforced sidewalls to resist flexing under heavy loads. This construction stiffness translates to a firmer ride, especially on rough roads, because the sidewall does not absorb as much impact. In contrast, P-metric tires are engineered with a more compliant sidewall to provide a smoother, more comfortable ride on paved surfaces.

Sidewall stiffness is not just about comfort; it also affects handling. An LT tire's stiffer sidewall helps maintain stability when the vehicle is heavily loaded, reducing sway and improving steering response. However, on an empty SUV, that stiffness can make the vehicle feel jittery and transmit road imperfections into the cabin. If you are deciding between the two, consider how the tire feels over the roads you drive most. For a deeper look at sidewall design, read tire sidewall stiffness.

Ride Comfort and Handling Trade-offs

The ride quality difference between P-metric and LT tires is often noticeable. P-metric tires are typically tuned for low noise, low rolling resistance, and a cushioned ride, which make them ideal for daily commuting and long highway trips. They also tend to be lighter, which can improve fuel economy. LT tires, on the other hand, are heavier and stiffer, which can increase road noise and reduce fuel efficiency, but they provide a sense of robustness and security when you are towing or hauling.

Handling also changes. An SUV on P-metric tires may feel more agile and responsive in daily driving, while the same SUV on LT tires might feel more stable and planted when carrying a heavy payload. The trade-off is that LT tires often have less grip on dry pavement because their tread compounds prioritize durability and load capacity over ultimate adhesion. For most drivers who do not regularly approach their vehicle's load limits, the comfort of P-metric tires is the better choice. For those who need maximum load capacity, LT tires are worth the ride penalty. See best light truck tires if you are leaning toward LT.

Choosing the Right Tire for Your SUV

Your decision should be based on how you use your SUV. Check the tire information placard on the driver's door jamb for the original tire size and load rating. If your SUV is not heavily loaded and you want a serene ride, stick with P-metric tires. If you regularly tow a trailer, carry a full load of gear, or use your SUV for work, LT tires provide the extra margin you need. Remember that you must maintain the proper inflation pressure for the tire type; LT tires often require higher pressures than P-metric tires. For inflation guidance, see tire pressure basics.

Many SUVs are offered from the factory with P-metric tires because they meet the needs of most buyers. If you choose to switch to LT tires, be sure they are the correct size and that the rims are approved for them. Also, be aware that LT tires may change the vehicle's speedometer reading and handling characteristics. For a selection of SUV tires, browse our best all-season tires for cars and SUVs. If you plan to do moderate off-roading, consider an all-terrain tire, as discussed in best all-terrain tires.

What to pick for your use

Questions

Can I use P-metric tires on my SUV if it came from the factory with LT tires?

Yes, if the P-metric tires have a sufficient load rating for your SUV's axle ratings. However, you must verify that the combined load capacity of the P-metric tires meets the GAWR listed on the vehicle certification label. LT tires are often specified for a reason, so check the owner's manual and placard before switching.

Are LT tires always stronger than P-metric tires?

LT tires are designed to handle higher loads and inflation pressures, but strength depends on the specific load range and construction. A load range E LT tire will typically support more weight than a standard load P-metric tire, but a lower load range LT may not. Always compare load ratings at the same inflation pressure.

Do LT tires affect fuel economy?

Generally, yes. LT tires weigh more and have higher rolling resistance, which can reduce gas mileage compared to comparable P-metric tires. The difference varies, but it is worth considering if you drive many highway miles and do not need the extra load capacity.

What is the main construction difference between LT and P-metric tires?

LT tires often have more plies or reinforced sidewalls to resist flexing under load. This makes them stiffer and more durable for heavy-duty use. P-metric tires use a lighter, more flexible construction to enhance ride comfort and reduce noise.

How do I know which load range I need?

Check your vehicle's tire placard and GVWR. If you plan to tow or carry heavy loads, choose an LT tire with a load range that meets or exceeds the maximum loaded weight each tire will support. For informed decisions, refer to tire load range for light trucks.