All-Terrain vs Highway Tires: A/T, H/T and M/T Explained

Three letters, three jobs

Truck and SUV tires mostly fall into three families, and the abbreviations on product pages tell you which one you're looking at.

• H/T, highway terrain. Built for paved roads.
• A/T, all-terrain. Built to split the difference between pavement and dirt, gravel or grass.
• M/T, mud-terrain. Built for mud, rock and soft ground first, pavement second.

Each step from H/T to M/T trades some on-road manners for more off-road bite. The right pick depends on where your miles really happen, and for most trucks in Broward and Miami-Dade, that's on the pavement.

Highway (H/T) tires

Bridgestone describes highway truck tires as optimized for paved roads, delivering a smoother, quieter ride and efficient everyday performance. They're the tires many pickups and SUVs leave the factory on.

Read Bridgestone's comparison the other way round and you get the highway tread: compared with an all-terrain tire, it has

• shallower tread,
• narrower grooves,
• smaller tread blocks,

all aimed at a smooth, quiet ride on asphalt.

Who they suit: commuters, highway miles, towing on paved roads, and drivers who never leave the pavement except for a gravel driveway or a grass lot at a ball game.

All-terrain (A/T) tires

Bridgestone's comparison is specific: all-terrain truck tires have deeper tread depth, wider tread grooves and larger tread block elements than a highway truck tire, which promotes traction off the pavement.

Firestone describes its all-terrain tires as built for vehicles that switch between irregular terrain and regular road, aiming for durability on dirt, gravel and grass while staying comfortable on pavement. BFGoodrich's off-road guide puts all-terrain tires in the middle, with better highway comfort and quieter running than a mud-terrain tire while still handling moderate trails.

Who they suit: trucks that see real dirt, sand or gravel on a regular basis. Think beach access roads, construction sites, ranch roads, boat ramps and hunting land, with plenty of highway between them.

The trade-offs

• Noise. Bigger blocks and wider grooves usually make more road noise than a highway tread. Makers have worked to bring that down, so read the maker's own claims for the specific tire.
• Ride. Compare what the maker says about comfort for the specific tire, especially if it's an LT size (more on that below).
• Tread life. Compare treadwear warranties tire by tire. Don't assume one family always lasts longer.

Mud-terrain (M/T) tires

BFGoodrich and Continental describe mud-terrain tires the same way: large tread blocks and wide voids that clear out mud, sand and soft soil and grip uneven surfaces such as rocks and ruts.

They're also open about the cost. BFGoodrich notes that the big, widely spaced blocks come at the expense of road noise, on-road grip and tread life.

Who they suit: trucks that spend real time in deep mud, rock or soft sand. If the trail days are a few weekends a year and the rest is I-595, an M/T is a lot of tire to live with every day.

Side by side

Use the table as a starting point. The tire maker's spec page for the exact tire you're considering is the final word.

What about rain and snow?

Florida drivers care more about a summer downpour than a snowbank.

Rain. None of these labels is a wet-grip rating. Look at what the tire maker says about wet traction for the specific tire, and keep an eye on tread depth as the tires wear. Our guide to tread depth explains why depth matters most in the wet.

Snow. Many A/T and M/T tires carry M+S, which is based on tread design rather than a snow test. Some all-terrain tires also carry the three-peak mountain snowflake, which means they met USTMA's measured packed-snow traction standard. If your truck heads north in winter, check for the symbol on the spec page. Our guide to all-season vs all-weather tires explains both markings.

Check the size type before you switch

Here's where people get caught out. Many all-terrain and mud-terrain tires are sold in LT (light truck) sizes or flotation sizes like 33x12.50R20, while the truck may have come with P-metric highway tires.

An LT tire isn't a drop-in swap for a P-metric tire:

• it carries a load range (C, D, E and so on) instead of standard or extra load,
• it needs different inflation pressures to carry the same load,
• and it can change ride and weight.

Our guide to LT vs P-metric tires covers load range and when a truck needs LT. Before you buy, compare the new tire's load index against your current one with the load and speed rating check.

And if you're also changing the tire's overall height, say going from a 265/70R17 to a taller size, check clearance and speedometer change first with the plus size calculator.

A quick way to decide

1. Where do 90% of your miles happen? Pavement points to H/T. A regular mix points to A/T.
2. What does the off-road part look like? Gravel and sand suit A/T. Deep mud and rock are M/T territory.
3. How much noise will you live with? Each step toward M/T usually adds some.
4. What does the placard say? Size, load index and speed rating still come first. The Tire Size Finder reads them off the door-jamb sticker.

Ready to compare? Shop tires by size. Extreme Tires installs at the Sunrise shop or by mobile van in Miami-Dade, Broward and Palm Beach counties; elsewhere in the 48 states and DC, your order ships to your address. See how installation works, or call (954) 773-1896 with questions about a specific truck.