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TL;DR
- None of the 11 mud-terrain tires in this library (11 brands) publish a mileage warranty, and none of the 11 carry the 3PMSF severe-snow symbol.
- New tread runs from 14/32in to 22/32in depending on model and size. A light-truck tire with 18/32in or more of tread is regulated under FMVSS 119, not the FMVSS 139 standard that covers most car and light-truck tires.
- UTQG treadwear grades don't exist for these tires: the federal rule covers passenger-car tires only and excludes deep-tread tires.
- Load range decides what a tire can carry. Nitto's Trail Grappler in LT285/70R17 is rated 2,755 lb at 50 psi as a Load Range C and 3,195 lb at 80 psi as an E.
- Federal rules require the tires on each axle of a truck to add up to at least that axle's GAWR, the rating printed on the door-jamb certification label.
At a Glance
Nitto sells a mud-terrain, a hybrid and a highway tire in the same size and load rating, which makes the tradeoff easy to see. All three figures are from Nitto's own size tables for LT265/70R17 Load Range E.
| Nitto tire (LT265/70R17 E) | Type | New tread depth | Tire weight | Mileage warranty |
|---|---|---|---|---|
| Trail Grappler | Mud-terrain | 18.9/32in | 60.81 lb | None published |
| Ridge Grappler | Hybrid-terrain | 16.4/32in | 54.48 lb | None published |
| Dura Grappler | Highway-terrain | 16.8/32in | 50.71 lb | 60,000 mi, P-metric and metric sizes only |
All three carry the same 3,195 lb maximum load at 80 psi. The mud-terrain is about 10 lb heavier per tire than the highway tire, and its tread is only about 2/32in deeper. The highway tire's LT size also has no mileage warranty, so in LT sizes the real difference is tread design and weight.
What Makes a Tire a Mud-Terrain
There is no federal or industry definition of "mud-terrain." It is a maker's label for a tread with large, widely spaced blocks and open channels that push mud and stones out as the tire turns. Makers describe the parts in their own terms. Cooper's Discoverer STT Pro has "Earth Diggers" shoulder scoops and "Mud Slinger 2.0" trenches. Yokohama's Geolandar M/T G003 has mud and stone ejectors that it says protect against stone drilling. BFGoodrich's KM3 uses what it calls Mud-Phobic bars to clear the tread. Nitto says the Trail Grappler's side lug blocks add biting edges, and Falken gives the Wildpeak M/T an aggressive upper sidewall for traction at low air pressure.
The only formal markings are about snow. The M+S mark on a mud-terrain's sidewall means the tread meets the USTMA snow-tire geometry: slots in at least one tread edge reaching at least 1/2in toward the center, at least 1/16in wide, and a contact-patch void area of at least 25%. That is a mold measurement, not a traction test. The three-peak mountain snowflake is a tested standard. The tire has to reach a snow grip index of at least 1.10 against the SRTT14 reference tire in the ASTM F1805-20 medium-packed-snow test. NHTSA describes M+S simply as "some mud and snow capability."
Which Federal Rules Apply to Mud-Terrain Tires
Most car and light-truck radials are built to FMVSS 139. That standard exempts light-truck tires with a tread depth of 18/32in or greater. Those deep-tread LT tires fall under FMVSS 119 instead, the standard for tires on vehicles over 10,000 lb GVWR. Most sizes of the Trail Grappler, Toyo Open Country M/T, BFGoodrich KM3 and Gladiator X-Comp M/T are at or above that 18/32in line.
Both standards require treadwear indicators, raised bars in the main grooves that show when the tire has worn to 1/16in. NHTSA's guidance is that a tire should be replaced at 2/32in. UTQG grades (49 CFR 575.104) cover passenger-car tires only and exclude deep-tread tires, so an LT or flotation mud-terrain has no treadwear number to compare. When a mud-terrain is also sold in a passenger or hard-metric size, only that size may carry a grade. Yokohama's G003 hard-metric sizes, for example, are graded 500 B B.
Load Range, Ply Rating and the Axle Rule
Almost every mud-terrain is an LT or flotation tire. Its load range letter maps to a ply rating, which is a strength rating, not a count of actual plies. Nitto and Toyo publish the same mapping: C is a 6-ply rating, D is 8-ply, E is 10-ply and F is 12-ply. Each step allows a higher inflation pressure and a higher maximum load.
An LT sidewall shows two load indexes, such as 121/118. The first applies when the tire runs single, the second when it runs as a dual on a dually rear axle. Goodyear's chart converts 121 to 3,197 lb and 118 to 2,910 lb. The same size can come in more than one load range, and the difference is large. Nitto's Trail Grappler LT285/70R17 is 116/113Q as a Load Range C, rated 2,755 lb at 50 psi. As a Load Range E it is 121/118Q, rated 3,195 lb at 80 psi.
The rule to check is in FMVSS 110. On a truck or SUV, the maximum load ratings of the tires on an axle must add up to at least that axle's gross axle weight rating (GAWR) on the certification label. Two Load Range C tires in that size give 5,510 lb per axle. Two E tires give 6,390 lb. If a passenger-rated tire is fitted to a truck, its rating is first divided by 1.10.
Tread Depth, Sizes and Speed Ratings by Model
The table is built from each maker's own size chart. Tread depth is new depth; wheel range and speed ratings cover every listed size.
| Tire | New tread depth | Load ranges | Size rows | Speed ratings |
|---|---|---|---|---|
| BFGoodrich Mud-Terrain T/A KM3 | 18/32" | C, D, E | 55 on 15–22in wheels | Q |
| Cooper Discoverer STT Pro | 18–22/32" (varies by size) | C, D, E, F | 47 on 15–22in wheels | Q, P |
| Falken Wildpeak M/T | 17.5–21/32" (varies by size) | C, D, E | 28 on 15–20in wheels | Q |
| General Grabber X3 | 18–21/32" (varies by size) | C, D, E | 18 on 15–20in wheels | Q |
| Gladiator X-Comp M/T | 18–19/32" (18/32" LT-metric sizes, 19/32" flotation sizes) | C, D, E, F | 36 on 15–26in wheels | Q, N, P |
| Goodyear Wrangler Territory MT | 15–17/32" (varies by size) | C, E | 7 on 17–20in wheels | S, Q, R |
| Hankook Dynapro MT2 | 15.5–18.5/32" (varies by size) | C, D, E, F | 16 on 15–20in wheels | Q, R |
| Maxxis Razr MT | 17–19/32" (varies by size) | C, D, E, F | 44 on 15–22in wheels | Q |
| Nitto Trail Grappler M/T | 18.3–21/32" (varies by size) | C, D, E, F | 65 on 15–26in wheels | Q, P |
| Toyo Open Country M/T | 18.3–21/32" (varies by size) | C, D, E, F | 84 on 15–26in wheels | Q, P |
| Yokohama Geolandar M/T G003 | 14–21/32" (varies by size) | XL, C, D, E, F | 74 on 15–24in wheels | Q, T, H |
Speed ratings are low across the category. Toyo's legend puts Q at 99 mph and P at 93 mph, and most mud-terrain sizes are Q. Goodyear advises replacing tires with an equal or higher speed rating than the original, and says that mixing ratings limits the vehicle to the lowest-rated tire. A truck that came on T-rated (118 mph) tires drops to 99 mph with a Q-rated mud-terrain.
Sidewall Construction, in the Makers' Words
Several makers market reinforced sidewalls on their mud-terrains. These are construction claims; no public standard rates sidewall puncture resistance, so compare them as descriptions, not scores.
- Nitto Trail Grappler: a 3-ply sidewall with high turn-up construction and thick rubber, on every size except the 15-inch ones.
- Falken Wildpeak M/T: 3-ply DURASPEC sidewall with two high ply turn-ups.
- Yokohama Geolandar M/T G003: GEO-SHIELD, which Yokohama describes as multiple sidewall plies, a full nylon cap and a high turn-up carcass.
- Maxxis Razr MT: an "armor" sidewall design and dual-core body-ply technology for casing strength.
- Cooper Discoverer STT Pro: Rock Climber sidewall, Stone Armor and Armor-Tek3 construction.
Toyo's rugged-terrain page gives a useful counterpoint. It uses 3-ply construction only on LT-metric and flotation sizes and 2-ply on P- and Euro-metric sizes, so construction can change within one model.
Weight and Fuel Use
Deep tread and extra plies add weight. In Nitto's charts, the Trail Grappler 35x12.50R17LT weighs 79.89 lb, and the LT265/70R17 weighs 60.81 lb against the Dura Grappler highway tire's 50.71 lb. NHTSA estimates that a 10% cut in rolling resistance improves fuel economy by 1 to 2%. Makers don't publish rolling-resistance figures for these tires, so weight and tread design are the only published signals to compare.
Nitto does publish a noise claim. It says 3D computer simulation of block size, shape and position made the Trail Grappler 34% quieter at street speeds and 36% quieter at highway speeds than its own Mud Grappler. That is a comparison against Nitto's more aggressive tire, not against an all-terrain.
Warranty Terms and When to Replace
With no mileage figure, the workmanship warranty is the only coverage, and its terms differ. Nitto replaces a tire free for uniformity problems in the first 1/32in of wear. For other covered conditions it replaces free while the tire is 25% worn or less and within 60 months, then charges the share of usable tread worn times the current dealer price. On a tire with 16/32in of usable tread worn down by 8/32in, that is 50% of the price. Gladiator X Comp covers workmanship for the original tread less 2/32in, but not past five years from the DOT manufacture date, and requires rotation every 6,000 miles.
For wear, check depth across the full width, not just the center. The legal and warranty floor is the 2/32in indicator bar. Age matters too. NHTSA notes that some vehicle and tire makers recommend replacing tires six to 10 years old regardless of tread. The last four digits of the DOT code give the build week and year: 3107 means the 31st week of 2007.
Every Mud-Terrain Tire in This Library
The 11 tires below are sorted by brand. The main tire library filter narrows the whole catalog by size.
The Mickey Thompson Baja MTZ P3 isn't listed below: it's discontinued, and Mickey Thompson's current mud-terrains are the Baja Boss M/T and Baja Legend MTZ.
How We Cover Mud-Terrain Tires
Specs come from each maker's own spec page. We do not buy, install or physically test tires; see how we rank. For the quieter, longer-warranty alternative, see all-terrain tires or the all-terrain vs mud-terrain comparison. Our best mud-terrain tires roundup has our picks.
Sources
- Nitto — Trail Grappler M/T product page and size table — 3-ply sidewall with high turn-up (excluding 15-inch sizes); side lug blocks; claimed 34% and 36% noise reduction vs the Mud Grappler; per-size tread depth, maximum load at pressure and weight (LT265/70R17 E 18.9/32in, 60.81 lb; LT285/70R17 C 2,755 lb @ 50 psi and E 3,195 lb @ 80 psi).
- Nitto — Ridge Grappler product page and size table — Ridge Grappler hybrid-terrain positioning, features, UTQG 500 A B on metric sizes, and per-size tread depth, overall diameter, width, rim range, maximum load at pressure and weight.
- Nitto — Dura Grappler product page and size table — 4-rib LT-metric and 5-rib P-metric tread designs, 60,000-mile warranty on P-metric/metric sizes, UTQG 600 A B, and per-size tread depth, maximum load and weight (LT265/70R17 E 16.8/32in, 50.71 lb).
- 49 CFR 571.139 — FMVSS No. 139, New Pneumatic Radial Tires for Light Vehicles (Cornell LII) — FMVSS 139 covers radial tires for vehicles of 10,000 lb GVWR or less but exempts light-truck tires with 18/32in or more of tread; treadwear indicators at 1/16in; LT tires must be marked with their load range.
- 49 CFR 571.119 — FMVSS No. 119, New Pneumatic Tires for Motor Vehicles With a GVWR of More Than 10,000 Pounds (Cornell LII) — FMVSS 119 applies to light-truck tires with a tread depth of 18/32in or greater; treadwear indicators must show wear to 1/16in (S6.4).
- 49 CFR 575.104 — Uniform Tire Quality Grading Standards (Cornell LII) — UTQG applies to new tires for passenger cars and excludes deep-tread, winter-type snow and limited-production tires; traction grade A requires a coefficient above 0.47 on asphalt and 0.35 on concrete.
- 49 CFR 571.110 — FMVSS No. 110, Tire Selection and Rims (Cornell LII) — The door-jamb placard lists the original tire size and cold inflation pressure; on trucks and MPVs the tires on an axle must add up to at least the axle's GAWR, and passenger tires are derated by dividing by 1.10 (S4.2.2, S4.3).
- USTMA — TISB Vol. 10, Snow Tire Definition for Passenger and Light Truck Tires (PDF) — M+S marking criteria: tread-edge slots reaching at least 1/2in toward the center, at least 1/16in wide, and at least 25% void area, all based on mold dimensions.
- USTMA — TISB Vol. 37, Definition for Tires for Use in Severe Snow Conditions (PDF) — The three-peak mountain snowflake symbol requires a snow grip index of at least 1.10 (SRTT14) or 1.12 (SRTT16) in the ASTM F1805-20 medium-packed-snow test, recognized by manufacturers.
- NHTSA — Tires (TireWise) — Replace tires at 2/32in; inflate to the vehicle placard, not the sidewall maximum; M+S means some mud and snow capability; LT sidewall single and dual load markings; DOT code date format; some makers recommend replacement at six to 10 years; a 10% cut in rolling resistance improves fuel economy 1-2%.
- Goodyear — Load Index and Speed Rating — Speed ratings Q 99, R 106, S 112, T 118 and H 130 mph; load index conversions to 120; replace with an equal or higher speed rating; mixed ratings limit the vehicle to the lowest-rated tire.
- Goodyear Canada — Tire Load Index Chart — Load index conversions above 120 (e.g. 121 = 3,197 lb, 123 = 3,417 lb, 126 = 3,748 lb) and why LT tires carry a second, dual-fitment load index.
- Toyo Tires — Open Country M/T product page — Speed-rating legend (N 87, P 93, Q 99 mph) and load range to ply rating mapping (C 6-ply, D 8-ply, E 10-ply, F 12-ply); Open Country M/T sizes and tread depth.
- Toyo Tires — Open Country R/T product page — Toyo positions the R/T between the Open Country M/T and A/T; 45,000-mile warranty; 3-ply construction on LT-metric and flotation sizes, 2-ply on P- and Euro-metric; stone and mud ejectors.
- Nitto — Limited Warranty and Owner's Manual, Replacement Passenger and Light Truck Tires (PDF) — Free replacement for uniformity issues in the first 1/32in; free replacement at 25% worn or less within 60 months; proration by usable tread worn; mileage warranties only for models listed on nittotire.com; replace at 2/32in.
- Gladiator X Comp (American Pacific Industries) — X Comp M/T product page — 36-row spec table (load index, speed, load range, tread depth, section width, overall diameter, M+S, single and dual loads) and the full US warranty text dated September 2026.
- Yokohama — Geolandar M/T G003 product page — GEO-SHIELD construction (multiple sidewall plies, full nylon cap, high turn-up), mud and stone ejectors, sizes and limited warranty terms.
- Maxxis — RAZR MT product page — Armor sidewall design, dual-core body-ply technology, off-road compound, and 17-19/32in tread depth by size.
- Cooper Tires — Discoverer STT Pro product page — Earth Diggers shoulder scoops, Mud Slinger 2.0 trenches, Rock Climber sidewall, Stone Armor and Armor-Tek3 construction; 18-22/32in tread by size.
- Falken — Wildpeak M/T product page — 3-ply DURASPEC sidewall with two high ply turn-ups and an aggressive upper sidewall for traction at low air pressure; no mileage warranty or 3PMSF claim.
- BFGoodrich — Mud-Terrain T/A KM3 product page — Mud-Phobic bars that clear the tread, CoreGard Max sidewall, and 18/32in tread depth.
- Michelin — Defender LTX M/S2 product page — 54 sizes, 50,000- and 75,000-mile warranty tiers, 13/32in tread (Michelin FAQ), the 275/55R20 F-150 treadwear test behind the 'two extra years' claim, the note that UTQG does not apply to light-truck sizes, and the +/-3% section-height and +/-4% width tolerance on published dimensions.