Underinflated tires flex more as they roll, building heat that can lead to tire failure. Low pressure can also increase fuel consumption and cause uneven wear.
A tire can look normal even when it has too little air. Regular pressure checks can catch the problem, but you also need to consider the setting you use, the weight you carry, and the tire’s condition.
1. Check Tire Pressure Before Each Travel Day
Tires lose air over time, even when the RV sits unused. Outside temperature changes can also affect pressure.
The U.S. Tire Manufacturers Association’s RV guidance recommends checking at least monthly, before each trip, and each morning you drive during a trip. That includes the spare and inner dual tires.
Use an accurate gauge rather than judging by appearance. Investigate unexplained pressure loss, and replace missing or damaged valve caps with suitable caps.
2. Check When Tires Are Cold
Your recommended pressure is a cold setting. According to NHTSA’s tire-maintenance guidance, a cold reading means the vehicle has been parked for at least three hours.
Early morning, before driving or direct sunlight warms the tires, is a good time to check.
Driving generates heat in the tires and raises their pressure. A warm reading reflects that change, so comparing it directly with the cold recommendation can be misleading.
3. Confirm the Recommended Pressure for Your RV and Tires
For tires that match your RV’s specifications, start with the recommended cold pressure on the vehicle’s tire label or in the owner’s manual. Follow any model-specific instructions for adjustments based on measured loads.
Label locations vary. Towables commonly have tire information near the front on the driver’s side. Motorhomes may have it in the driver’s door frame, around the driver’s seat, or at the entry door.
The sidewall number can match the vehicle recommendation. Some manufacturers specifically call for that setting: Carlstar’s trailer-tire FAQ, for example, recommends the maximum PSI listed on the sidewall, checked cold.
Changed tires or conflicting instructions call for confirming the recommendation with the RV and tire manufacturers. Any selected cold pressure must stay within the tire, wheel, and valve ratings.
Our guide to what your RV tires should be inflated to explains when to follow the vehicle label, sidewall guidance, or a load-and-inflation table.
4. Weigh Your RV and Check Its Limits
Load the RV as you travel, including occupants, supplies, fuel, and the water you normally carry. Compare its loaded weight with the gross vehicle weight rating, or GVWR, and each axle’s weight with its gross axle weight rating, or GAWR.
A truck-stop scale can help check total and axle weights. Individual wheel-position weighing provides more detail because an axle can be within its rating while one side is overloaded.
Extra air cannot raise the RV’s weight ratings. Remove weight or correct its distribution if you exceed a limit.
Use a load-and-inflation table when the instructions for your RV and tires support that method. Michelin’s RV tables require matching the tire’s markings and using the heavier axle end to select pressure for all tires on that axle. Its tables list loads by axle end, including the combined load on a dual pair.
Keep the same recommended cold pressure across each axle. Front and rear axles may need different settings.
5. Check the Spare’s Pressure and Condition
Include the spare in your regular checks, even if it has never been used. Inspect it for damage and aging as well as air loss.
Follow the RV manufacturer’s instructions for inflating the spare tire. Avoid automatically matching it to another tire, especially on a motorhome with different front and rear pressures.
Before a full-size spare goes into service, confirm that it is suitable for that position and inflated to the required pressure.
6. Use a TPMS Alongside Manual Checks
A tire pressure monitoring system can warn you about pressure loss while you drive. Some systems also display temperature readings or provide high-temperature alerts.
Configure the system according to its manufacturer’s instructions using your confirmed cold-pressure settings. Continue checking pressure and inspecting the tires manually.
An alert calls for attention. Pull over somewhere safe and assess the problem rather than continuing to drive while watching the number fall.
7. Don’t Bleed Air to Correct a Normal Warm Reading
Pressure normally rises during travel. Releasing air to bring a warm tire down to its cold recommendation can leave it underinflated after it cools.
A tire losing pressure during a trip still needs prompt attention. Waiting for a cold reading is no reason to keep driving on a low tire.
If a tire has been run flat or seriously underinflated, get professional help before reinflating it or driving farther. Internal damage can make reinflation dangerous. In a dual arrangement, both tires need inspection because the companion tire may have carried too much weight.
8. Inspect Tires and Follow Their Replacement Guidance
Look for sidewall cracks, bulges, cuts, uneven wear, and other damage. Have a tire professional assess concerning changes, including recurring air loss or unusual vibration.
Replacement timing depends on the tire manufacturer’s guidance, its condition, and how it has been used and stored. Good tread alone cannot establish that a tire is fit for continued service.
For example, Michelin’s RV guide recommends annual professional inspections after five years in service and replacement at ten years from manufacture, including spares. Damage, wear, or operating conditions can require earlier replacement. Follow the guidance applicable to your tires and RV.
Do I use the tire pressure the RV manufacturer recommends, or do I use the pressure the tire sidewall recommends? I have a travel trailer.
The placard is the correct starting point. The sidewall is the maximum limit. The most accurate pressure comes from actual loaded weight plus the tire manufacturer’s load chart.
My load range E tires I inflate to 80psi + – due to gauge accuracy. I di this cold/early morning at ambient temp. Is there a problem with that.
That sounds fine. Checking them cold in the early morning is the correct method, and a slight variation around 80 PSI due to normal gauge accuracy is not a problem. Just make sure 80 PSI matches the recommended cold pressure for your RV and tires.