The correct tire pressure for your RV is based on the actual loaded weight on each axle, not the maximum pressure printed on the tire sidewall. To find the right pressure, get the RV weighed fully loaded for travel, then look up the recommended PSI in the tire manufacturer's load/inflation table for your specific tire size and weight. Running sidewall max pressure on a lightly loaded RV creates a harsh ride, uneven wear, and reduced traction — and under-inflating is the #1 cause of RV blowouts.
Most likely causes (in order of likelihood)
- Always measure pressure cold — before driving, when tires haven't been in the sun. Pressure rises 1 PSI per ~10°F of temperature change.
- Never let a tire run more than 5 PSI below the calculated correct pressure — under-inflation causes sidewall flex, heat buildup, and blowouts.
- Replace tires by date, not just tread. RV tires age out after 5-7 years regardless of mileage due to UV and ozone degradation.
- Check pressure before every trip and weekly during extended travel.
- Use a quality TPMS (tire pressure monitoring system) for real-time monitoring — under $200 and prevents the most common cause of RV roadside failures.
Diagnostic steps (in order, free/cheap before expensive)
- Weigh the RV fully loaded for travel — water tanks at travel level, cargo loaded, occupants in the vehicle. Use a CAT scale at a truck stop (typically $12-$15) or seek out an RV-specific 4-corner weighing service (ideal but harder to find).
- From the scale ticket, identify the weight on each axle. For travel trailers, this is the trailer axle weight. For motorhomes, it's front axle + rear axle (often dual rear).
- Divide axle weight by 2 (single axle) or by 4 (dual rear) to get per-tire load. Add 10% as a safety margin.
- Look up the tire manufacturer's load/inflation table for your exact tire size and load range. Match your per-tire load to the corresponding PSI.
- Use that PSI as your cold tire pressure baseline. Add 5 PSI if you frequently travel in hot weather to compensate.
DIY vs. call a tech
100% DIY. The CAT scale at any truck stop will weigh the RV. Tire manufacturer load tables are available free online (Goodyear, Michelin, Continental, etc.). A handheld pressure gauge accurate to 1 PSI runs $15-$30.