My Tires Are How Old?

Quick—how old are the tires on your Airstream?

If you’re like most people, you haven’t thought about that in a while, and you might even be wondering why you should be thinking about it now. The short answer is that tires eventually get too old for safe use, even when the tread still looks good.

For recent owners, here’s the shocker: having bought a new travel trailer or motorhome doesn’t actually guarantee that the tires are new too. That’s because the Airstream may have sat on a dealer’s lot for a while, or (if it was a trade-in) it might have had the tires swapped.

Tires have a finite lifespan even if they aren’t being used, and that lifespan begins from the moment they are manufactured, not when they are placed into service. There’s really only one way to be sure of the manufacture date of your tires, and that’s to get up close and personal with your tires.

Every tire has a date code imprinted right into the rubber on the sidewall. It’s four digits, printed in a little box like the one shown in the photo. This box only appears on one side of the tire, so it’s possible that if you can’t find it on it on the outside, you’ll have to slide under the trailer to look at the tire’s other side. Bring a flashlight and a notepad so you can record the date code for each tire—they may all be different.

Tire date code

Deciphering the four-digit code is easy. The first two digits are the week the tire was manufactured, the second two digits the year. For example in the photo above, “2115” means the tire was manufactured in the 21st week of 2015. That’s mid-May, 2015, which isn’t bad because the tires were purchased in August. It’s not unusual for tires to sit around in a warehouse for a month or three between manufacturer and purchase.

If your tire only has a three digit code, replace it now! Tires with 3-digit date codes were made before the turn of the century.

The tire industry has varying recommendations on when you should replace tires. Some manufacturers say four years, others say as long as ten years. But the actual lifespan of a tire varies depending on how it is used, so if your tires have seen a rough life (lots of storage time, exposed to the sun, under-inflated occasionally, lots of potholes, etc) you should probably err toward the side of caution and replace them after four or five years—no matter how good they appear.

New buyers should check date codes too. The dealer will probably be surprised that you even knew to ask about the tire date codes (and imagine their faces when you slide under the trailer to look at the date code yourself!) but at the same time this shows that you’re a serious buyer and you have done your research.

Why you need tire pressure monitoring

Roslyn B. says, “I have a question about trailer tires. This past weekend I had a blowout on a busy interstate. We spent two hours in 102 degrees in a precarious position waiting for the emergency assistance from Good Sam to get to us. Thankfully a FHP trooper waited with us hoping to slow the traffic speeding by on I-275.

We had the tires on my 19-foot Airstream checked out prior to our trip. The tire was only two years old. Any thoughts on what to do to prevent this from happening again? We keep it stored in an inside facility in Orlando.”

We feel you, Roslyn. A tire pressure monitoring system that allows you keep track of your tire performance might be your best option. When installed, a remote monitor in your tow vehicle tells you when a tire becomes dangerously under- or over-inflated.

Tire pressure monitors are quickly becoming a necessity rather than the newest gadget out in electronics land. Every new passenger vehicle and light truck produced or sold in America has a TPMS system for good reasons.

People are fast becoming believers, due to the fact that they’re hearing stories from other RVers or that they’ve had a near disaster or worse and experienced tire failures themselves. To most folks, TPMS systems seem complicated and difficult to understand, so we’ll try to give a “non-geek” explanation of how they work. They really aren’t that complicated or mysterious.

Tire Pressure Monitoring Sensor

First, these systems are completely wireless. This means that they have no wires running from the sensors to the monitor installed on the driver’s side dashboard area. They operate on frequencies that allow them to communicate back and forth from the sensors to the monitor. The system is constantly requesting the temperature and pressure from each sensor installed on every tire on the vehicle.

When the sensor is ‘asked’, it responds with an answer, giving the monitor the data and then displaying that information on the screen for the operator to see. Settings are established in advance so that the system understands what the high and low pressure and high temperature settings are supposed to be. As long as the tire stays within those setting parameters, the system remains quiet and displays that all is well.

If, however, the system detects tire anomalies (a fancy engineering word for ‘the system is out of established limits’), the monitor immediately goes into an alert mode, and lights and sirens go off to give the driver the opportunity to make quick educated decisions about the issue before it becomes critical.

If a nail or screw is picked up in a tire, a brake begins to drag, or a hub bearing fails, these (and other issues) can cause air pressure, the lack of pressure, or even heat to become a problem. The system immediately jumps to the problem tire or tires, and lets the driver know exactly which tire is in trouble—possibly preventing a catastrophic event.

Tire Pressure Monitoring Sensor

Sometimes the TPMS doesn’t alert the driver to a blowout in advance of it occurring, for a simple reason: if there is a catastrophic occurrence that takes place instantly—such as hitting a piece of debris or a very sharp-edged pothole—the tire fails instantly and there’s no way that the system can tell the driver ahead of time that that’s about to happen.

In any case, keep vigilant and make sure you are not driving on old tires. (The date of manufacture may be much older than the purchase date.) Make sure that you have your tires properly inflated, and weigh your trailer at a truck scale to make sure it’s not overloaded.

The TST tire pressure monitoring system is available in the Airstream Life Store.

Tire Tips—Part 2

[Want to read Part 1 of this article?  Click here]

“Ignoring your tires can result in really expensive damage,” writes Rich Luhr, publisher of Airstream Life magazine and author of Airstream Life’s (Nearly) Complete Guide to Airstream Maintenance. “When a tire blows out or is run flat, it often throws off chunks of tread which whack the Airstream and damage the body. It’s not uncommon for a on-the-road tire failure to cause $1,000-2,000 in secondary damage. So let’s get to know our tires and prevent that.”

Luhr and other experienced Airstreamers offer the following tips for buying and maintaining your trailer tires—and steps to take when they fail.

How long do tires last?

“That depends on a lot of things,” said Jon Gold, presenter of a well-received safety seminar during Alumafiesta in Tucson this year. “They last until they wear out, break, get dry rot, or you don’t like the looks of them anymore. A year, or eight years. The best way to get the longest life out of your tires is put in correct air pressure,” he said.

“The second best way is to cover the wheels on the sunny side where you park your Airstream while it’s stored. Ultraviolet radiation from the hot sun causes them to dry out and get checks,” (weather-check cracking). “If you see checks on your tires, it’s time to change them even if you have tread. If a tire doesn’t look good to you—it has a bubble, or a nail—of course, get it fixed or get a new one.”

Nitrogen. What?

Some claim that filling tires with nitrogen will improve performance and gas mileage. “Some nitrogen is good, sure,” said Gold. “But air is 78 percent nitrogen. If you’re a race car driver it might make a difference, but if you’re towing an Airstream with a maximum speed of 65 miles an hour” (the optimum speed for tire care, according to Gold), “it won’t. Just put in air. If you’re obsessive compulsive and you’re someplace that offers nitrogen, go ahead.” Prepare to lighten your wallet, though; a nitrogen fill averages $6 per tire.

Buying tires

“You can buy a brand new tire that’s one month old, or a new tire that’s six years old. The price is the same. Which would you rather have?” said Gold. The answer seems obvious, and there’s a way to find out when a new tire was manufactured. Look at the four-digit code in the oval on any American-made tire—the last two numbers are the year it was manufactured; the first two numbers are the week of the year it was made. (Examples: 0111 means that tire was made during the first week of 2011. 5213? The 52nd week of 2013. You got it.)

“You can say, ‘I want a tire that’s less than six months old, and I’m going to check’,” said Gold. Make sure new tires in the shop were stored properly—on their sides, not on the treads.

Goodyear vs. Michelin

Your Airstream comes from Jackson Center with Goodyear Marathon trailer tires. “I’m not a fan,” said John Irwin, long-time Airstream owner and frequent contributor to Airstream Life magazine. “I’ve had multiple problems and blowouts over the years. I went from those to E-rated truck tires and they were worse! They failed just as often, and when they did they tore up the trailer. They shed tread but retain air, so the tire monitor doesn’t always go off when they fail and they can be back there beating the heck out of the side of the trailer.”

Irwin now uses Michelin light truck tires on 16-inch wheels. “I’m convinced those will take care of me,” he said. “They’re worth the cost—$1400, whatever—particularly for long distance travel.” Airstream began installing Michelins on the Eddie Bauer, and made the upgrade available for other models when customers clamored for better tires.


Airstream tire blowout“Blowouts are rare, but if you do happen to get a flat tire, blowout, or loss of air, do NOT jam on the brake,” said Gold. “Hit the gas pedal, regain control of vehicle, then take your foot off the gas and look for a safe place to stop.”

“If you brake, you put more weight on the flat and it will yank you in that direction,” he explained. “It’s counterintuitive, but instead grab the steering wheel, hit the gas pedal real quick to lighten the weight on the front, then back off. If you see or hear or feel a tire going flat, maintain control, and gradually pull over. Don’t just yank over to the side, cutting people off.”

What about a slow leak?

“If I’m on the highway and know I’m losing air, I’d rather go to a good tire shop, even if I have to go thirty miles to find one,” said Irwin. “I carry a bottle of Fix-A-Flat and put some of that in there and keep going.” Look at the labels on tire sealants. “Some have a warning that they’re dangerous for anybody who has to work on that tire later,” said Irwin. “Choose one that’s safe. It will usually cost a couple dollars more.”

Be prepared with the items you’ll need to fix a flat:

  • Breaker bar with extension and socket
  • Leveling blocks
  • Visibility: fluorescent vest, flares, flashers or cones
  • Tire pressure gauge
  • Torque wrench
  • Torque stick (only if you might let a shop put the wheels back on for you)
  • Mechanic’s gloves (optional, to keeps your hands clean)

How to change a tire

Changing Airstream tire“Everyone calls it ‘changing a tire’ but what you are really doing is changing a tire and wheel assembly. The wheel is the metal part, the tire is the rubber part, and you are going to remove them as one piece,” explained Luhr. “Later, a tire shop will remove the tire from the wheel to patch or replace it.” If you get a flat, stay calm and follow his step-by-step instructions:

1.Airstreams don’t come with the tools you need to change a tire, so it’s up to you to obtain the necessary tools and carry them in the Airstream. The lug nuts on most Airstreams require a 13/16” socket, but some may need a 3/4” socket. You’ll also need a 1/2” drive wrench (also called a “breaker bar”) and a 6” or longer extension, or a cross-type lug nut tool. To put the lug nuts back on correctly, you should have a good quality torque wrench, also in the 1/2” drive size.

2. If you are working by the side of the road, it’s a good idea to put out some flares, orange cones, or whatever you might have to warn people zooming by. At the very least turn on the hazard lights on the tow vehicle—they’ll flash the Airstream’s taillights too. Make sure you’re visible as well, by throwing on a reflective safety vest or shirt.

3. Get the spare tire and wheel out of its carrier. Check the air pressure in the spare. If it’s low, you should add air to get it up to the recommended pressure. A tire that is low on air is likely to blow out, which could make things a lot worse. If the pressure in the spare is more than 15% low and you can’t add air, you might consider three-wheel towing for a short time.

4. Next, loosen but do not remove the lug nuts of the wheel you need to remove. This is because it will be difficult to loosen those nuts once the wheel is off the ground. If you can’t get the nuts off with your arms, try positioning the wrench so you can put your foot on it.

5. Once the tire is back on the ground, you must finish tightening the lug nuts to the factory spec. The correct torque is extremely important. Under the right amount of tension, the wheel is drawn to the brake hub face and the lug bolt will be well mated with the lug nut. Too much torque and the lug bolt will be stretched, and eventually break. Too little tension and the lug nut can work off.

6. You can’t judge the correct tightness accurately by feel, so you need to carry a torque wrench, and instructions on how to use your torque wrench should come with it. For most torque wrenches you set the target torque in foot-pounds and the wrench will “click” when you’ve tightened the nut to that setting. Remember to re-set your torque wrench to zero when you are done with it.

7. Check the Owner’s Manual or documentation for the wheels to verify the correct torque, and make a note somewhere of that number so you have it handy when you have to replace a wheel.

8. Don’t let tire shop personnel put your wheels on with an air wrench. Air wrenches can put out far too much torque and overstress the lug bolts. Instead, insist they use a manual (hand) wrench, or get a “torque stick” rated for 60 ft-lbs and have them use that. Then tighten the nuts to the correct torque specification with your torque wrench. Better yet, just tell the tire shop to give you the wheels when they are done, and you can put them on yourself. That way you know it will be done right. Use the torque wrench only to tighten the lug nuts, never to remove them. It’s a calibrated instrument that can go out of whack if you use it to remove nuts.

9. It’s very important to re-check the lug nuts after the trailer has been towed for a while. This is because the lug nuts need a little time to “seat” properly. A common recommendation is to check the lug nuts with your torque wrench after 25 miles, then again at 50 miles, and one last time after 100 miles from when you changed the tire. If you don’t check and re-tighten the lug nuts to proper torque, they may loosen over time, which can lead to losing a wheel.

If you missed Tire Tips — Part One, find the complete article here.

Tire Tips—Part 1

“Your tires do a big job, and they don’t ask much of you in return,” writes Rich Luhr, publisher of Airstream Life magazine and author of the new Airstream Life’s (Nearly) Complete Guide to Airstream Maintenance. “Just keep them inflated, inspect them periodically, and replace them when they get too old or worn.”

Luhr and other Airstream experts share their top tips about trailer tires in this and the next issue of Outside Interests.

Tire pressure: the magic pill

What’s the easiest way to better your ride, decrease your tire wear, and improve braking and road handling? “Correct your tire pressure,” said Jon Gold, presenter of a safety lecture during a recent Alumaevent.

Tire inflation illustration
“You want your tire to look like the one in the middle of this diagram,” said safety presenter Jon Gold.

“When you’re under-inflated, you’re riding on your sidewalls, the thinnest part of your tires,” explained Gold. “You’re asking for a blowout.” The optimum tire pressure for your Airstream is hidden in plain sight on the side of your coach, on a metal plate.

“Typically that number is either 50 or 65 psi,” writes Luhr in his maintenance guide. “The tire pressure should reflect the loaded weight of the trailer.” If your Airstream rolls on factory-issued Goodyear Marathon ST (Special Trailer) tires, see Goodyear’s Load/Inflation tables online to determine the right psi. Incorrect pressure can cause uneven wear and other problems—some severe.

Invest in a good tire pressure gauge,

and use it before every trip (and after you set out on the road again after camping for awhile). “Buy a good brass gauge with a short piece of hose,” advises John Irwin, Airstreamer and contributor to Airstream Life magazine. “That makes it easier to get it on the valve stem without losing a lot of air in the tire.”

“Keep the gauge with your trailer tools, along with a 12-volt DC air pump with an extension cord,” suggests Luhr. “It’s a nuisance trying to find an air pump at a gas station when you need a top-up, and often difficult to get close enough to it with your trailer. Having an AC-powered air compressor at home is a convenience, too.”

Consider a tire pressure monitoring system

Keep track of your tire inflation with a TPMS. “These systems typically use sensors screwed onto the valve stems, or placed inside the wheel,” explained Luhr. “A remote monitor in the tow vehicle will alert you if the tire becomes dangerously under-inflated, or over-inflated, usually from overheating of the brake or wheel bearing parts.”

“You want to know what’s going on with your tires because often you won’t feel or see a change in tire air pressure. On multi-axle Airstreams it’s even possible to lose a wheel entirely and not feel any change in towing characteristics,” he said.

Knowing immediately what’s going on can save you a lot of trouble. Buy a quality TPMS; “this is a case where you’ll get what you paid for,” said Luhr.

Installing a TPMS means you’ll know the pressure of each tire moments after you get in your tow vehicle, every time you tow. “No more bending down and checking each tire one at a time, no more getting your hands dirty, and less time spent getting ready to tow,” Luhr said. “Don’t forget to buy a spare monitor for the spare tire, so you don’t have to slide under the Airstream to check it before every trip.”

“Tire monitoring systems will catch most threats in most cases,” said Irwin. Owner of several Airstreams and other trailer models through the years, he offers this tip: “When underway, and you’re stopped at a stop light, reach over and punch through all the tires in the system, and look for any tire that doesn’t match the others. If one is very high and hot, something’s wrong. If one is low, you could have a slow leak, or worse.” Keep in mind that pressure varies with the temperature of the environment—it climbs when tires get hot, and drops as tires cool. “The sunny side can be higher than the shady side,” Irwin said.

When and how often to check pressure and inflate?

Because of temperature changes and normal leakage (losing one to two psi a month is expected) check your tire pressure once a month. During a trip, check them weekly.

There’s no need to remove air when tire pressure increases during the day, and don’t stress out about temporary altitude changes, (such as heading up the hill for a day of skiing)—the correct pressure is the one you put in when your tires are cool before you start your day of driving. If you move to a new campsite with a significantly different altitude, adjust your tire pressure the following morning.

Do a walkaround and look for signs of trouble whenever you inflate. “Check your tires for bulges,” said Irwin. “Does it look like a bicycle tire? If it’s round, the pressure could be way too high, or it could be a slipped belt.” Check for thrown (delaminated) treads, bulges in the tread, isolated worn patches, and rapid wear in an isolated area.

Want more?  Read Part 2 by clicking here!

How to Weigh Your Airstream, part 1

When you ‘stream by a truck stop and notice a “weigh station” sign, are you tempted to pull off and see what your rig weighs? Most new (and many expert) Airstreamers are intimidated to join the line of 18-wheelers—but don’t be. Most RVers report that they have a pleasant experience at the scales.

“It’s not scary to weigh your trailer,” said Jon Gold, Alumafiesta seminar leader. “And everyone should weigh their Airstream to make sure you haven’t exceeded any gross weight capacities.” Here’s how:

Load it up

Weigh your trailer when you are fully packed, “when you’ve got everything in it, ready for a trip,” advised Gold. “Food, water, clothes, pots and pans…anything you’re going to take along.” This also includes passengers and pets, and a full tank of gas.

Look for a CAT sign

—big and yellow, with a friendly cat’s head logo. A Certified Automated Truck Scale (“CAT Scale” is a franchise business) can be found “at most truck stops,” said Gold. “It’s only ten dollars, and if you weigh your trailer once when it’s fully loaded, you don’t have to do again.”

Pull up onto the scale until your driver’s side window is even with the intercom sign; painted lines on the scale will guide you as well. You’ll be required to push a “call button” that may be situated high above your head. (You could stand on your running board to reach it, or take this tip from those in the know: bring a stepstool, or better yet, a broom handle to punch the button.)

Have your trailer license number ready. A “weighmaster” will greet you, guide you through the process, and tell you when you’re done. Pull away, park, and walk into the building to get your scale ticket at the fuel desk. (The computer printout you receive includes gross vehicle weight as well as individual axle weight.) That’s all there is to it!

(Want more detail?  See our followup article on using the CAT scales)

Weigh twice

Typically a truck scale will provide three separate weights: front axle, rear axle, and trailer axles (all counted together). To get started you’ll need a baseline. Take your first trip through the scale without your trailer, so the report will reflect the amount of weight on each axle of your fully loaded tow vehicle. (Find the Gross Axle Weight Rating [GAWR] for both the front and rear axles in your vehicle owner’s manual, or on the sticker inside the driver’s side door jamb.)

Now hitch up your Airstream and pass through the scale again. This time your report will show all three axle weights: front, rear, and trailer.


Compare the two reports, line by line. The trailer weight should be below the Gross Vehicle Weight Rating (GVWR) stated by Airstream. Find these specs for your coach on the serial number plate on the lower front streetside of the body, or on a sticker on the inside of a mid-closet door about 60″ from the ground. (2009 and later trailers also have max cargo weight on a sticker on the screen door.)

If you exceed any weight ratings—

“take stuff out,” said Gold. “I worry about the people who go to the Gem and Mineral Shows,” he laughed. “But don’t take out the tool kit!” It’s easy to overload your Airstream without even knowing it. If your trailer is too heavy, you must reduce your cargo before going further.

Tire inflation matters

An overweight Airstream and under-inflated tires are a bad combination. Look on the sidewall of your tire for the recommended tire inflation pressure and adjust accordingly, and stay on top of optimum tire pressure with a good monitoring system; find one at the Airstream Life store. “When you’re rolling down the road, it’s almost impossible to feel when a trailer tire loses air pressure,” cautioned Rich Luhr, Airstream Life publisher. “Most people find out far too late.” The tire pressure monitors—as with all items in the store—“are the things we tell our friends about,” said Luhr. “Things that can save your Airstream from disaster, or improve your travel experience.”