If you own a motorhome, you generally don’t have to worry about whether the correct tires are installed on your unit as long as you are having a certified tire shop do the work. However, it is worth mentioning load range ratings. The load range is a measure of the ply rating, indicating the relative strength of the tire plys and therefore how much load the tires can safely carry. The load rating is indicated on the sidewall by a letter, with higher letters indicating a higher load range. When replacing your tires, always make sure the load rating is the same or higher than manufacturers specification. If in doubt, contact a tire center or the RV manufacturer.
Another important metric for trailer owners is tire type. There are distinctly different requirements for the tires on a towable than for the vehicle doing the towing. The towing vehicle requires a lot of traction, so the tires must be designed to allow for grip, acceleration, cornering, and braking. The sidewalls are quite flexible to contribute to passenger comfort.
On the other hand, trailers are followers. For this function, sidewall flexion is undesirable, especially on trailers with high centers of gravity. Flexing of tire sidewalls is a major contributor to trailer sway. Special Trailer (ST) designated tires should always be used on towable RVs. ST tires are constructed of more heavy-duty materials than standard vehicle tires, have much more rigid sidewalls, and operate at higher inflation pressures. These features help prevent sway. Since both ST and Light Truck (LT) tires are fully rated for trailer use, some owners install LT tires on their trailers, as they are often less expensive. I highly recommend using ST tires on all towable units for the reasons specified above.
In addition to ensuring you have the proper tires and correct inflation pressure, make sure you always have an evenly distributed load. This is essential to proper tire and vehicle performance and also contributes greatly to safety. Proper load distribution can help enhance vehicle handling, improve fuel economy, prevent irregular tire wear, maintain braking ability, extend tire life, and protect major RV components from excessive wear.
Most motorhome and trailer tires are designed for a maximum speed of 65 mph. Although many people like to travel at speeds higher than this, it is important to bear in mind that fuel economy suffers significantly at speeds above 55 mph, so slow and steady is never a bad thing when it comes to RV travel. Plus, it allows you to enjoy the scenery more.
Perform regular inspection and maintenance on your RV tires. Have your wheels balanced whenever new tires are mounted or moved to a different position, after a flat repair, or anytime a tire is mounted. Have your tires rotated as per manufacturer recommendations. If you notice uneven or abnormal wear of the tire tread, you should have a wheel alignment done. Perform regular visual inspection of the tires and valves and note that, in general, tires should be replaced when they reach five years from manufacture date or the tread depth reaches the manufacturers specified depth, whichever comes first. Since 2000, the manufacture date is stamped on the sidewall as the last four numbers of the data code. The first two numbers are the week of manufacture, and the last two digits are the year. Replacement recommendations are guidelines, but will be affected by temperature, humidity, storage conditions, etc.
About the Author:
Steve Froese, an avid RV owner, traveler, and Coach-Net member since 2013, is the principal of “A Word to the Wise Technical Communications”, a published RV author, certified RV technician, and licensed Professional Engineer. He frequently collaborates with the “RV Doctor”, Gary Bunzer, and has worked with the RVIA/RVDA as a technical and training writer and consultant. Professionally, he works as a quality engineer and musician. Watch for more of Steve’s work in upcoming Coach-Net publications.
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