Tire Types, Load Ratings & Performance Explained
For truck and SUV owners, choosing the right tire goes far beyond size. The tire type, load capacity, speed rating, and tread depth all play a critical role in safety, handling, and long-term durability.
Tire Load Index & Load Range
The load index is a numerical code that indicates how much weight a single tire can safely carry when properly inflated.
For example, a load index of 121 means the tire can support over 3,000 lbs. Multiply that by four tires, and you can see why load rating is especially important for trucks and SUVs.
In addition to load index, many truck tires use a Load Range designation:
- Load Range C – Light-duty use, softer ride
- Load Range D – Medium-duty hauling
- Load Range E – Heavy-duty towing and payloads (10-ply rated, up to 80 PSI)
If you tow trailers, haul equipment, or carry heavy cargo, choosing the correct load range is essential to prevent overheating, blowouts, and uneven wear.
Speed Ratings – More Than Just Top Speed
[Image of tire speed rating chart]The speed rating is a letter that represents the maximum speed a tire can safely maintain under load. Common ratings include:
- S – up to 112 mph
- T – up to 118 mph
- H – up to 130 mph
- V – up to 149 mph
Even if you never drive at high speeds, a higher speed rating usually means better heat resistance and more precise handling.
Seasonal Tire Types Explained
Summer Tires
Summer tires are designed for warm temperatures and dry or wet pavement. They offer excellent grip but lose effectiveness in cold weather.
Winter Tires
Winter tires use special rubber compounds that remain flexible below 45°F. They feature deep grooves and biting edges for snow and ice.
All-Season Tires
All-season tires are the most popular choice in the US, providing balanced performance in dry, wet, and light snow conditions.
Tread Pattern Types (H/T, A/T, M/T)
- Highway Terrain (H/T): Quiet, smooth, and fuel-efficient. Ideal for daily driving.
- All-Terrain (A/T): Balanced for road use and off-road traction. Very popular for trucks and SUVs.
- Mud-Terrain (M/T): Aggressive tread for mud, rocks, and trails. Loud on pavement.
Why Tread Depth Is So Important
Tread depth directly affects traction, braking, and water evacuation.
- New tire: ~10/32 to 12/32 inch
- Replace for wet safety: 4/32 inch
- Legal minimum: 2/32 inch (not recommended)