RV Tire Blowouts: Why 104°F Heat Causes Failures

Thirty percent. That’s the share of all highway accidents involving large vehicles that the National Highway Traffic Safety Administration attributes to tire failure, and the most common cause of that failure isn’t a nail in a campground gravel lot or a pothole on a back road in rural Montana. It’s heat buildup from running underinflated tires at highway speed. I’ll be honest: when I first read that number, I figured it was one of those stats that sounds scarier than it is. Then I blew a rear dual on my 2017 Thor Motorcoach somewhere outside Amarillo on a 104-degree afternoon, watched $340 worth of tire shred itself across two lanes of I-40, and developed a very different relationship with tire pressure.

Eight years in, I still meet full-timers who treat their RV tires like passenger car tires. Check them occasionally, replace them when they look worn. That approach will eventually catch up with you, and it tends to do it at 65 mph.

The Numbers That Should Make You Nervous

The NHTSA estimates that roughly 11,000 tire-related crashes occur annually on U.S. highways. For large recreational vehicles specifically, the Tire Industry Association has documented that the leading cause of RV blowouts is operating tires below the manufacturer’s recommended cold inflation pressure, not age, not road hazard, not cheap tires. Underinflation causes the tire sidewall to flex more than it’s designed to, generating internal heat that breaks down the structural integrity of the rubber and steel belts from the inside out. By the time the tire looks low, you may already be past the point of safe operation.

What surprised me was how small the margin is. A tire that’s 20% underinflated (say, running 75 PSI in a tire rated for 95 PSI) generates roughly twice the heat of a properly inflated tire at the same speed. The RV Safety & Education Foundation has published guidance showing that tire pressure drops approximately 1 PSI for every 10-degree Fahrenheit drop in ambient temperature, which means a tire you checked at 85°F in the morning can be meaningfully underinflated by the time you’re rolling at noon in a different elevation.

That’s the physics piece. The age piece is where I see even experienced RVers get it wrong.

Age Is Not a Suggestion

I thought for years that tire age only mattered for tires that looked cracked or dried out. The visible sidewall cracking is the late-stage symptom, not the early warning sign. What the industry knows, and what Michelin, Goodyear, and Continental all formally state in their RV tire guidance, is that most RV tires should be replaced at 5-6 years regardless of tread depth and regardless of mileage. Some manufacturers say 7 years as an absolute ceiling. This is not conservative marketing to sell more tires. The rubber compound degrades from UV exposure and oxidation at the molecular level long before you can see it.

Here’s how to find your tire’s birthday: look for the DOT code on the sidewall. The last four digits tell you the week and year of manufacture. A tire stamped “2319” was made in the 23rd week of 2019. That tire, as of July 2026, is seven years old and has no business being on a highway.

I’ve crawled under a lot of rigs at rallies and checked DOT codes for people who genuinely didn’t know this existed. One couple in a 2016 Coachmen Freelander had all four original tires from the dealer. Every one was from 2015. They’d put fewer than 18,000 miles on the rig and assumed the tires were fine.

What a Proper Tire Pressure Monitoring System Actually Does

A TPMS isn’t optional for me anymore. Not after Amarillo. The question is which type, and the answer is more nuanced than most product review articles will tell you.

There are two categories: valve-stem cap sensors (external) and internal sensors that go inside the rim. External sensors like the TireMinder A1A (currently around $159 for a four-sensor kit) are easier to install and can be moved between rigs, but they’re exposed to theft, road debris, and cross-threading risk. Internal sensors, which typically run $250-$400 installed professionally, are more accurate and not vulnerable to theft but require a tire shop for installation and tire swaps.

For most Class A and Class C owners, I’d point you toward the TST 507 series. It’s what I run, and the monitor display inside the cab is readable at a glance without squinting. The flow-through sensor design means you can still add air without removing the sensor, which sounds minor until you’re at a truck stop at 7 AM and the guy in line behind you is impatient.

Real-world example: A reader named Paul, who full-times in a 2021 Tiffin Phaeton, told me his TST system alarmed at 5:48 AM outside of Flagstaff, Arizona last fall when a rear tire dropped to 87 PSI from a slow bead leak. He pulled over safely in the dark, added air, limped to a shop at opening time. His alternative, without the system, was to not know until 65 mph on the highway later that morning.

Load Rating, Weight, and the Mistake Almost Every New Full-Timer Makes

This one costs people real money and real safety margin, and it’s almost never discussed in the YouTube “first year RVing” content. Every RV tire has a load rating. That rating assumes the tire is inflated to the maximum pressure listed on the sidewall. If you’re running lower pressure, your effective load capacity drops.

The practical version: if your Class A is close to its GVWR when loaded, and you’re running your tires at 85 PSI instead of the 110 PSI maximum, you may be exceeding the tire’s load-rated capacity even if you’re technically under the coach’s GVWR. The two numbers interact.

The solution is a CAT scale weigh-in (around $14 at most truck stops) to find your actual axle weights, then match your inflation to those weights using the tire manufacturer’s load/inflation table, not just the door placard number. I’ll be honest, I didn’t do this for my first three years on the road. The door placard said 95 PSI and I ran 95 PSI and assumed that was that. What surprised me was learning that Michelin’s own load tables for my specific tire showed I should have been running 102 PSI given my actual rear axle weight, confirmed by a CAT scale weigh-in in Barstow.

Scenario: Full-timer in a 36-foot Class A, fully loaded with water, food, tools, and two bikes on the rack, pulls onto a CAT scale. Rear axle reads 14,200 lbs, which is within GVWR. Tire manufacturer’s load table shows each tire in the dual configuration needs 105 PSI to carry that load safely. Driver had been running 95 PSI. Adjusted pressure and replaced tires that were six years old. Zero tire incidents in two subsequent years of full-timing.

What to Actually Do Before Every Trip

Not a checklist in the generic sense. Here’s the physical routine that I actually do, in the order I do it:

Check cold pressures first thing in the morning before the rig has moved. “Cold” means at least three hours since the last drive. Use a quality dial gauge (I use a Milton S-921, about $22, and I’ve confirmed it matches the readout on my TST system consistently). Hit every tire including the spare. If the spare is a full-size, it needs to match the others; if it’s a temporary, check your manufacturer’s recommended pressure for that specific unit.

Then walk the tires. Run your hand across the tread face. You’re feeling for cupping (a wavy surface suggesting alignment or balance issues), unusual wear patterns, or embedded objects. Look at the sidewalls for any bubbling, which means internal delamination and means you park and call a tire service.

Then look at your load. If you added gear or took on water since the last weigh-in, mentally account for it.

This takes about twelve minutes for a six-tire setup (four duals, one tag, one spare). It is by far the highest-return-per-minute safety task on any rig.

Sources

• National Highway Traffic Safety Administration (NHTSA): Tire-related crash data and underinflation statistics referenced in highway accident reporting
• Tire Industry Association (TIA): Industry guidelines on RV tire underinflation and blowout causation, including heat generation data
• RV Safety & Education Foundation (RVSEF): Published guidance on tire pressure management, age-related degradation, and RV-specific recommendations
• Michelin North America Tire Load/Inflation Tables: Manufacturer-specific load and pressure matching charts for commercial and RV tire applications
• Federal Motor Carrier Safety Administration (FMCSA): Large vehicle tire maintenance and inspection standards, applicable to Class A motorcoach operation

Photo: Kampus Production via Pexels