Most RV owners think they are taking proper care of their tires. After all they periodically check the pressure, take a quick glance or “whack” with a trucker’s bat, and keep them clean. Tires are the most important component on an RV, but according to data assembled by the RV Safety & Education Foundation and several tire manufacturers, are also the most neglected.
Most RV owners inflate tires to the PSI (pounds per square inch) stamped on the side of the tire which is actually the maximum pressure at maximum weight or GVWR rating! Proper tire pressure can only be found by weighing each wheel individually and checking the tire manufacturer’s chart for dual or single application. This is different from most passenger cars as the weight of your RV can be substantially higher once you put all your “stuff” inside. If your rig is not loaded to maximum capacity, you will be overinflating the tire by using the number on the sidewall and have less tread on the ground which will affect stopping and maneuvering.
You can weigh your rig at any Cat Scale found at most larger truck stops such as Flying J and Pilot. Visit www.catscale.com for the nearest location. These scales have three platforms allowing you to put each axle on a platform. Trucks and trailers would put the front axle of the truck on the first, back axle on the second, and the trailer axles on the third. Motorhomes would put the front axle of the motorhome on the first, back axle on the second, and a tow vehicle on the third.
This will give you axle weights which you can use to divide the number of tires per axle and determine the weight, but will not give true individual weights. Depending on how you load your rig and the weight of appliances and options, some rigs are heavier on one side. It’s best to get individual wheel position measurements which can only be done with portable scales. Visit www.rvsafety.com to find what dealers or locations the RVSEF teams are weighing coaches to get precise weight info.
The next step to proper tire maintenance is physically checking tire pressure EVERY time you hit the road. Just glancing at the “bulge” in the tire or hitting the tire with a trucker’s bat is not good enough, especially on larger rigs. If your tires are 10 PSI less than recommended pressure you reduce your weight carrying capacity by 25%! And you cannot visually tell the difference between tires that are 10 PSI difference in most cases. Get the gauge out and get the gauge tested by a certified tire shop yearly. I like the Tire Pressure Monitor System (TPMS) that have a wireless feed to a screen inside the drivers compartment that not only tell me the pressure of the tire (inside dual included) but also the tire temperature. Well worth the price of a tire blowout.
When we drive our cars and trucks on a daily basis the centrifugal force pushes softening components from the rubber to the outside of the tires and keeps them from drying out. On an RV we often drive to a specific location and let them sit for days, weeks, months! This prolonged exposure to the elements dries out the sidewall and develops cracking known as weather checking. It’s important to inspect the sidewall periodically for weather checking. Also, if you want to make the sidewall “shine” with an aftermarket spray, make sure it has no alcohol components or others that will enhance the drying effect. And cover the tire if it will be exposed to the elements for longer than one week.
Tires have a date stamped on the sidewall known as a DOT ID stamp. This code has information including the plant it was built in, the size, and most important, the date. The last four digits indicate the week and year the tire was manufactured. Tires are only rated for a 10-year life cycle. It’s not uncommon to find tires on a new rig that are much older as they are often purchased in quantity and stored until the unit is sold. Check the date and replace if they are older than 10 years.
Periodically you should check the thread of your tires to look for improper wear patterns, low thread, and missing chunks of tread (really!). If you notice thinner thread on the inside or outside of the tire it means you have alignment issues or improper weight distribution. Running your hand over the tread will also indicate early signs of alignment issues if the thread is smooth in one direction and rough or “feathered” in the other.
The Rubber Manufacturing Association recommends any vehicle over 10,000 pounds should have at least 4/32” of tread. Vehicles under 10,000 pounds should have 2/32” of tread. Use a good depth gauge and check your tires periodically.
With a little bit of annual inspection and maintenance you can properly detect any issues before they become a problem, keeping your tires in top shape for your next long haul.