RV Tires: Age Limits, Load Ratings and When to Replace

Knowing when to replace RV tires is the safety call owners get wrong most often, because RV tires rarely wear out — they age out. A trailer that covers 3,000 miles a year can show deep, healthy tread on a tire whose rubber has quietly oxidised into blowout territory, and a motorhome tire can look showroom-fine while its sidewall is crazing. This guide covers the rules that actually govern RV tire life: the date code, the load ratings, correct inflation, storage damage, and the costs of a replacement set — so replacement is a planned purchase, not a roadside event.

The Date Code Is the Deadline

Every tire carries a DOT code ending in four digits: the week and year of manufacture — 3221 means week 32 of 2021. That date, not the tread, sets the retirement clock:

Trailer (ST) tires: most manufacturers and tire-industry guidance put service life at roughly three to six years, with five a common planning number for tires that sit in the sun.
Motorhome and LT tires: guidance from major makers generally lands at five to seven years, with professional inspection annually from year five and an absolute ceiling around ten years even for a tire that "looks new" — Michelin, for example, publishes inspection from five years and removal at ten for its tires.

Sitting is not rest: rubber compounds include anti-ageing agents that are worked through the tire by rolling. A stored RV's tires age faster than a daily driver's, which is why low mileage never extends the date. When you buy, check the codes on the new set too — a "new" tire can be two years old on the shelf. Tires are also a standing item on our RV maintenance checklist: a date-code audit takes five minutes once a year.

Load Ratings: The Number That Must Exceed Your Axle

An RV tire must carry its share of the rig's actual weight with margin. Three markings matter:

Load range / load index: Load Range D, E, F (and beyond) on ST tires corresponds to rising ply ratings and maximum pressures (65, 80, 95 psi and up). The tire's maximum load in pounds is moulded on the sidewall.
ST vs LT: Special Trailer (ST) tires have stiffer sidewalls built for trailer loads and sway; Light Truck (LT) tires are common on motorhomes and some heavy trailers. Fit the type and size the RV manufacturer specified — the placard on the rig is the authority, not the internet.
The scale is the truth: published dry weights exclude your cargo, water and options. The worked examples in our guide to RV towing weights explained show how to weigh an axle and compare it honestly with the tire's rating. Running at or over the rating — especially under-inflated — is the classic recipe for a tread separation.

Upgrade load range when replacing, if the wheels allow it: a higher-rated tire run at its proper pressure carries the same load with more margin. Never exceed the wheel's own pressure and load rating, which is stamped on the rim.

Inflation: Pressure Is Load Capacity

On an RV tire, air pressure is the load rating — under-inflation lets the sidewall flex beyond design, building heat until the tire fails. Rules that keep you out of trouble:

Check cold, before every trip, with a gauge that reads to your maximum pressure. "Cold" means before driving, not after the fuel stop.
Trailers: ST manufacturers commonly direct inflation to the sidewall maximum when the load requires it; at minimum, follow the load/inflation table for your actual scale weight — never below the placard figure.
Motorhomes: inflate to the table value for the weighed axle load, matched across each axle, and reweigh after big packing changes.
Fit metal valve stems if you run pressures above about 65 psi or add TPMS sensors — rubber stems are a quiet failure point. A tire pressure monitoring system, typically a few hundred dollars, earns its cost the first time it warns of a slow leak before the tire overheats.

Weighing: The Appointment That Settles Arguments

Every load and pressure decision above depends on one number most owners guess: what each axle — ideally each corner — actually weighs, loaded as you travel, water and all. A truck scale pass costs roughly $15 as of October 2026 and takes ten minutes: weigh the whole rig, then each axle, and compare every figure with the axle rating and the tires' capacity at your inflation. Motorhome owners can go further with individual corner weights at RV weighing services, which catch the classic one-side-heavy slide-out rig that axle totals hide. If the scale says a tire is at 98% of its rating on a normal Tuesday, the fix is not hope — it is a higher load range at replacement, redistributed cargo, or less cargo. Guessing is how a tire ends up both overloaded and under-inflated, the two failures that account for most blowouts between them.

What Actually Kills RV Tires

Age and UV: oxidation and sunlight crack sidewalls (check the sunny side in storage; covers help).
Under-inflation and overload: as above — heat is the mechanism of almost every blowout.
Flat-spotting and storage: months in one spot on hot asphalt or bare ground; park on pads and move the rig occasionally.
Road damage and dual mismatch: on motorhome duals, a diameter mismatch makes one tire carry both shares; replace duals as matched pairs and never run one new tire beside a worn one.
Speed: many ST tires carry speed ratings that older guidance capped at 65 mph; check the sidewall letter on yours and drive within it.

Warning signs that mean replace now, whatever the calendar says: sidewall cracks deep enough to see cord, bulges, tread separation, uneven wear pointing to alignment or axle problems, a casing that has run flat, or repeated pressure loss.

After a Blowout: The Mate Is a Suspect Too

When one tire lets go, its partner on the same axle (or the other dual) has just carried double load at speed, possibly under-inflated by the event itself — tire makers and fleet practice treat it as damaged until proven otherwise, and many owners replace the pair. Inspect the rim for cracks and bends before fitting anything to it, check the suspension and brake wiring the flailing tread may have whipped, and look at the wheel well and floor above: tread separations routinely tear wiring, plumbing and underbelly on their way out. Document the damage before cleanup if insurance might be involved. A blowout is also diagnostic — if the cause was age, the whole set shares the birthday, and the correct response is the set, not the single.

What a Set Costs, and How to Buy

Budget with the date, not the tread. Typical fitted prices as of October 2026: trailer tires roughly $100–$300 each in common sizes (more for high load ranges), 16-inch LT tires for heavy trailers and smaller motorhomes roughly $200–$400 each, and 22.5-inch motorhome tires roughly $400–$700 each — a six-tire Class A set, at several thousand dollars, is the spike year in an ownership budget. Don't forget the spare: it ages on the same clock, and a seven-year-old spare is a get-you-to-the-tire-shop device at best. Replace in axle sets at minimum, keep the date codes of a set within a year or so of each other, and have the shop balance motorhome and trailer tires alike — vibration is wear on everything behind the axle, not just the tire.

Mobile tire services and RV repair shops can supply and fit at your storage lot or home; find tire and service providers through the RV Frontier provider directory. Tires are the one system where the calendar outranks your eyes: read the date code, respect the load table, keep the pressure honest, and the set you buy on schedule is the blowout you never have.