Ask Dave: Is it OK to tow my older trailer at highway speeds?

Dear Dave,
I have a 2009 r·pod 171 by Forest River that I tow with a 2021 Toyota Tundra. Since the trailer is an older model, is it OK to tow it at today’s highway speeds? —Robert

Dear Robert,
Over the past 20+ years I have worked with the RV Safety & Education Foundation (RVSEF) helping to develop their nine-topic safety training program along with videos. They have done extensive research on towing, driving, tires and other safety factors. Their most important statement when it comes to towing is: There is a big difference between towing legally and towing safely. And, in your case… Is it OK?

There are many factors to consider when addressing safe towing such as tires, axles, weight ratings, hitches, and road conditions. Also when you are talking “highway speeds,” are you referring to interstate or just state highways? Most state highways are posted at 55 mph, which is typically safe for towing a trailer unless there are adverse weather conditions, which we will cover later.

If you are including interstate travel, that could be up to 75 mph in states like Nebraska, Colorado, and others. Some states have restrictions on vehicles towing. It gets a little confusing as several websites list different speeds, and some have the restriction on a vehicle towing a “mobile home.” Most states have information signs posted as you cross the state line that help identify what speed restrictions they have.

Safe tire speed

Most trailers have ST-type tires, which are special trailer tires. The Tire and Rim Association rates them for 65 mph. I am not a tire expert, although I did stay at a Holiday Inn Express near a Goodyear Dealer once. But I would suggest you read the article from tire expert Roger Marble here.

Proper tire pressure

When I first started working with RVSEF back in the late 1990s, their data showed that more than 75% of RVs had underinflated tires. We did see a huge issue with tire failures during that time. Most RV owners do not check their tires on a regular basis. Since most trailers do not have a tire pressure monitor system (TPMS), they just glance at the tires before leaving on a trip.

Just 10 psi below recommended pressure reduces carrying capacity of the tire by 25%. Typically it is not noticeable by just looking at the tire, kicking it, or hitting it with the “trucker’s bat” and listening for the proper thump. Running down the road with low tire pressure at highway speeds will build up heat—and that is asking for trouble. Check your tire pressure before each trip.

Tire inspection and protection

Tires are the most vulnerable component on an RV—but the most neglected. Exposure to the sun dries out the sidewall and creates weather checking or small cracks that eventually become larger and weaken the sidewall. Most tire manufacturers do not recommend the tire shine products as it enhances the degradation. Rather, they recommend just washing the tire with a mild detergent and covering them to protect them from the sun. Anything more than 1/8” of a crack on the sidewall should be considered dangerous and the tire should be replaced.

Inspect the tread to see if there is abnormal wear on the edges, center, or a cuffing of the material. Run your hands side to side across the tread. If it’s smooth in one direction and rough in the other, it is a start of a bad wear pattern and an indication of an alignment issue.

Braking ability

Your r·pod most likely has an electric auxiliary brake for the axles. However, weight and speed also factor into the equation of whether or not it is safe to tow this trailer with your Tundra at highway speeds. Even with the auxiliary brake, it will most likely take almost twice as much distance to break at higher speeds. So the consideration is your ability to monitor that situation in case of an emergency.

Axles and bearings

Most axle companies do have a recommendation for maximum speeds, especially when loaded to maximum GVWR (Gross Vehicle Weight Rating). They also recommend to visually check and repack the bearings once a year. However, I always carry an infrared temperature gun and while driving, check the hub, brake drum, and tires once a day. A sudden spike in temperatures will tell you something is going on inside that drum and bearing assembly, and you will need to check it more often.

Is it OK to travel at highway speeds with this older trailer?

Sometimes I get accused of not answering the question, and this might be one of those times. In my opinion, if you take the precautions to adhere to the rated speed of the tire and axles, and verify the weight and performance of all the components, I believe you can safely tow your trailer at a highway speed that falls into those parameters. But I do think 65 mph is the maximum, unless speeds are posted lower, of course.

 You might also enjoy this from Dave 

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Dave Solberg is a leading expert in the RV industry and the author of the “RV Handbook.”

Read more from Dave here. 

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