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Your motor home is equipped with truck tires. Under normal circumstances and with proper maintenance, you should receive thousands of miles of trouble-free service.

They are usually the weak link in the system. If tire ratings are exceeded, they are likely to fail. The failures are usually due to progressive damage. It's a slow, insidious process. The only solution is proper tire maintenance and proper inflation. Wash your tires to help prolong their life. Wash both sides (!) to remove goo and road dust, but do not use a petroleum based product. It will pull the rubber out of the tire.

Example of a tire: LT235/85R16, LRE. The "LRE" means load range E. Years ago we looked at tires by the number of plies. This is no longer the case, as many good tires now can be only a single ply. But it's exceedingly tough. Load range E is the equivalent to the old "10 ply rated" tire. The code here is -- the letter "E" is the fifth letter. Multiply it by 2, and you get the "10". Load range G is 7 multiplied by the magic "2" again, or a 14 ply equivalent rating.

Tire information includes "Max Load Single" at some tire pressure, such as 80 psi COLD. This means that the maximum load can only be carried when your tire is inflated to that pressure. Keep in mind that if you drive on a "80 psi cold", it could go to 90 or more after you've driven for a while. That's OKAY! Don't let any air out, or you'll be driving on an underinflated tire.

As coaches get larger and heavier, and since customers think it looks “better” to have a coach with a higher silhouette, tires are becoming larger and taller.

The 275/80 is the largest coach tire used for our Intrigue. The 275 number refers to the distance of the cross section width of the crown of the tire -- stopping short of the bulge. The 80 is a percentage of that number wheel rim to tire top.

Some common tire problems include sidewall cracking. Often caused by the sun, cover your tires whenever possible, expecially if the coach will remain in one position for a longer period of time. Do not use tire dressings (Eagle One products [which we believe they sell] were recommended, however.)

For safety and maximum tire life, proper inflation pressure must be maintained. Properly inflated tires also contribute to overall motor home stability and safety. Refer to the tire section in your chassis operator's manual for information on maintenance, inflation pressure, and tire care. 

NOTE: Check the wheel covers periodically. They could work loose during driving. 

Replacement tires must be the same size, and have at least the same weight carrying capacity as the original

equipment. All tires of the same size and rating may not have the same weight carrying capacity. Consult your tire dealer. The original equipment tires supplied on your motor home have weight carrying capacities to support gross axle weight ratings (GAWR) as stated on t

Federal Certification Tag located on the sidewall near the driver's seat.

In case of sudden tire failure, avoid heavy brake application. Gradually decrease speed. Hold steering wheel firmly and move slowly to a safe, off-road place. Park on a firm level spot, turn off the ignition, and turn on the hazard flasher system. 

The spare tire is located in an exterior storage compartment. 

NOTE: Your motor home is not equipped with a jack. 

Even with good tire maintenance and normal driving, you may experience a flat tire. Summon professional help through your auto club or travel service, or a local truck service facility. Your motor home is not equipped with a jack or other lifting device. Do not attempt to lift the motor home with a jack Consult the Chassis Operator's Manual for additional information on tire inflation and proper torque.

 WARNING

TO AVOID PERSONAL INJURY AND/OR PROPERTY DAMAGE IF A BLOWOUT OR OTHER TIRE DAMAGE OCCURS, OBTAIN EXPERT TIRE SERVICE HELP. DO NOT ATTEMPT TO CHANGE THE TIRE YOURSELF. 

Always make sure your tire rim diameter and the rim/wheel diameter are identical. Whenever possible, use tires of the same pressure on an axle. Use the higher pressure when two tires are unequal, as over inflation is far better than under inflation. If you change to tires of a greater load capacity, you will be able to use a somewhat lower tire pressure.

As coaches get larger and heavier, and since customers think it looks “better” to have a coach with a higher silhouette, tires are becoming larger and taller.

The 275/80 is the largest coach tire used for our Intrigue. The 275 number refers to the distance of the cross section width of the crown of the tire -- stopping short of the bulge. The 80 is a percentage of that number wheel rim to tire top.

To determine what tire pressure to use, weigh the coach after it is loaded. Loaded means all water and fuel as well as the “stuff” you will pack into the coach. This cannot be done at the factory, as many wish, because the coach will not have been loaded at this point. Only after the individual loaded weight is known for each wheel can a recommended air pressure be utilized using the load and inflation tables. Be sure not to exceed the tire rating. Tire manufacturers do not recommend overinflating to cure weight problems. Stick to what is printed on the sidewall.

Some common tire problems include sidewall cracking. Often caused by the sun, cover your tires whenever possible, expecially if the coach will remain in one position for a longer period of time. Do not use tire dressings (Eagle One products [which we believe they sell] were recommended, however.)

Air Gauges

Recommended is a “180 reverse air gauge” which can get at both interior and exterior tires. Valve extensions are nor recommended, as the vibrations between the two dual tires can cause air leakage. Anything you add to the tire valve can lead to potential problems.

What Causes Delamination (“alligators”)?

This could be caused by a bad tire from the start. Impact with a curb or like impediment bruises and weakens the tire. Heat must be present for delamination to occur, and this can come from underinflation, which weakens the sidewall and causes heat.

Pressure

When you check your tire pressure, do it before you start up in the morning. If, for example, you were driving through a desert like area, it is very possible that it would take several hours for the tires to cool enough to get a reliable tire pressure reading.

Coach tires are probably due for rotation after about 25,000 miles. It is recommended that they be rotated as follows: move the front tires to the right hand rear. That set of duallies now becomes the front two tires. At the next rotation, rotate the front wheels to the left hand rear.

To determine what tire pressure to use, weigh the coach after it is loaded. Loaded means all water and fuel as well as the “stuff” you will pack into the coach. This cannot be done at the factory, as many wish, because the coach will not have been loaded at this point. Only after the individual loaded weight is known for each wheel can a recommended air pressure be utilized using the load and inflation tables. Be sure not to exceed the tire rating. Tire manufacturers do not recommend overinflating to cure weight problems. Stick to what is printed on the sidewall.

Get the Right Tire Pressure

You need a tire chart, showing maxim loads at different minimum tire pressures. However, tire charts assume that the load will be exactly evenly distributed. Of course it will not. As a practical matter, find the heaviest side by weighing the good he'll have one.) You should have steel valve stems. Try to avoid extenders. They deteriorate and break.

There is a relationship between load limits and speed. Tire manufacturers measure service life at a sustained speed of 65 mph. Over that, tires lose carrying capacity. Service life can be extended by lower speeds.

Tires & Transmitters

This is about tire monitors in a coach. Transmitters are wireless, and xmit to monitor mounted near driver. Small antennae in back of unit receives signal, and monitor displays data on each of six tires..

Sensors are mounted with stainless steel strap to inside of tire. They have lithium battery on a kinetic switch. As motion occurs, the're flipped on, and they transmit information. The warranty is for 3 yrs/50K miles. But actual experience is closer to 7 years on commercial trucks, with "expected" life of 7 yrs or 70,000 miles. .

What does it do? Why do you need it?

Peace of mind. It monitors actual pressure (right now) in each tire. It toggles between each of the six tires on a motorhome.

It also monitors temperature. We care about air pressure because it creates heat. If you can guard against temperature, you can best monitor and mange tires. Heat always occurs BEFORE a problem. Gives driver an early warning. Monitoring temperature is the most important feature.

If you know temperature, you also know "required" pressure. You first tell it what the cold pressure should be. It's the RV owner's responsibility to know what it should be for his own coach.

It will tell you whether you are over inflated or under inflated based on the "slope" -- the changing requirements as heat builds as the RV is underway.

WARNING

Two forms of low pressure warnings. Low pressure alert is more like an advisory. If you have 100 psi cold pressure, first warning level might be set to 92 psi. Any time it gets to 92 or less, an early "alert" (red light) comes on. Next is a "warning" which might be set at e.g. 90 psi. Third warning is where tire gets above a certain temperature. Truck industry recognizes that any sustained tire pressure above 195-200 psi will cause tire failure. Coming down hills w/brakes on will heat the tires. Problem is where you're on straight road and the heat goes up. Tire separation, sidewall deterioration, etc. may not be far behind. Going across the desert at 115 degrees, asphalt might be 140 degrees. Long term driving over 200 degrees will cause tire failure. Slow down, or even stop and let it cool.

What about tow car? There's a need, but no solutions yet. (??? I thought I saw one...)

Status: Difference between actual and required pressure. It's a built in sloping warning device. Start at 100 psi might go to 120 psi. "Required pressure" is now 120 psi too. Don't want to wait until tire pressure drops 30% before a warning is given. As air pressure ramps up, tire pressure ramps up, but status floats w/the new "required pressure" -- so if you're down 8-10 pounds, you'll get same warnings. Again, temperature is really what you want to be monitoring, so this is probably the most valuable feature.

All the programming is done at the monitor using two buttons. Entire programming sequence can be done from "setup" throught the various parameters used for your own coach.

Any overlap of signals from a nearby coach also equipped with SmarTire? If so, warnings would go off. It's conceivable, since they're on the same frequency. But it retransmits every 30 seconds, so any false readings would be momentary and quickly corrected.

Recommends "unplugging" after the day's trip. Nothing is transmitted until you start moving. So when you first fire up in the day, tire pressure isn't registering. You need to drive a few blocks.

One RVer with the SmarTire installed reported --Temperature: O/S temps in AZ at 100 degrees, registering 185 degrees; slowed to 60 mph and the tire pressure dropped 10 degrees.

Note: 127 pounds is the highest it will display (this can be a problem for coaches with high "cold" pressures.)

Temp will be more important. Inside dually will have less airflow, and two inner duals will run "hotter".

Push both buttons to 'standby' -- it shows six dots. One way to leave it while underway.

Accuracy of pressure compared to air gauge. Gauge is +/- 3 pounds; SmarTire is +/- 1 pound.

Problem: Intermittent operation of inside duals. When antenna is pulled out, that seems to solve it.

NOTE: This is going to be replaced by a newer model that will not have the 127# limit, and monitor more tires. Will be entirely newly designed system.

Status: Warnings should be around 12-15.

Bottom Line -- Better fuel economy with less tire wire, and enhanced safety.

What About Duallies?

Note, if you have two tires together, the tires will be de-rated. Two mounted as duallies will have a lower rating than when the same tires are used as singles.

Tire Life

Is very much a function of inflation pressure. If radial tires are either over- or under-inflated, we'll lose a significant percentage of tire service life. Heat is the death of tires. Underinflation causes abnormal tire deflection, builds up heat and causes irregular wear. If you overinflate the tire only the center of the tread will touch the road and you may not have enough road contact. A dangerous situation.

Age of Tires is Significant

Some RVs are 10 years old and only have 40,000 miles. The tread may still be good -- but the tires fail. No one knows how long tires will last. Under normal use, a tire has a useful life somewhere in the ballpark of 5 -- 7 years. Interestingly, you'll get more carcass life out of your tires if they are used. 

TIP: When you rotate your tires, keep the spare tire in the rotation, and it will last much longer. You should have steel valve stems. Try to avoid extenders. They deteriorate and break.

There is a relationship between load limits and speed. Tire manufacturers measure service life at a sustained speed of 65 mph. Over that, tires lose carrying capacity. Service life can be extended by lower speeds.

The Department of Transportation requires that on one side of each tire there be a long set of letters and numbers which gives among other things, the date of manufacture. Look only at the last 3 numbers. The first two represent the week of the year in which it was manufactured, and the last digit is the year in the decade. Thus the number 164 would indicate the tire was manufactured in week "16 ", and the"4" would indicate 1994. Some tire manufacturers add other coded information. TIP: Since tires have a limited life, be sure when you're buying to look for the date of manufacture -- and don't buy tires which are already well aged!

Right Ways and Wrong Ways to Block Tires

This is largely due to the fact that sidewalls often have steel in them. Look at the label. When blocking, be certain the blocks cover the entire footprint. Otherwise the steel sidewalls can crimp, and subsequently fail. Block both tires on duallies, preferably with one block.

Please read our Chocks, Locks & Blocks page for more information.

Tire Rotation

You wouldn't need to except in the case of:

1. Uneven wear.
2. To get the spare in the rotation. to keep it from drying out. Not to need to rotate tires rarely happens. Don"t put unequally worn tires on in dual situations. Motorhomes have unique problems, the front tires break but do not accelerate. This can and will cause uneven wear. The tires should be rotated side to side to even this out.

Rims

If you change tires to ones of a different load rating, check your rim rating. The rims need to be able to handle the new tire psi.

Tips for the next time you buy an RV! You need some honest, straight answers about RV vehicle weight. You should be confident enough to ask all the right questions.

• A good first question is how much weight do you want to carry? If you're going to carry a lot of stuff, know what your net carrying capacity should be. In general, most people carry at least 2,000 pounds. This includes everything except fuel. Full timers need at least 3,000 pounds NCC. This will be on the new label. But also, check the GVWR, and then weigh it to find what the true dry weight is. You'll then have a "verified empty weight".
• Consider weight distribution. Check where the storage areas are, and where the tanks are. Some water tanks are 100 gallons -- that's over 800 pounds of water. Is it located somewhere near the center of the coach?
• Look at the floor plan. Is it balanced side to side? Where's the generator? Is all the storage on one side?

All RVs have wheels, tires and axles in one form or another. Tires have ratings for weight load, inflation, temperature, speed, rim width, rim spacing for dual wheels, etc.. Axles have weight ratings (some light ones even have speed ratings). The tires on a particular axle need to be inflated to the pressure specified for that weight load by the tire manufacturer. Proper inflation extends tread life, prevents tire overheating, and improves fuel economy by reducing rolling resistance. Understand that all tires on a vehicle may not need the same inflation pressure, but all tires on the same axle do. The tires on the front axle can require a different pressure than the rear axle, which can be a different pressure than the trailer tires. The key point is that each tire needs to be inflated to the correct pressure for the axle load it is supporting. Tire manufacturers publish ratings for their tires; ask your tire manufacturer's dealer for a copy of the table of "Inflation Pressures Vs Weight Ratings" that apply to each tire size and model on your rig. Check inflation pressure when the tire is cold; that is, before it is driven more than a mile; not less than three hours after you have stopped driving; and, not after the tire has been exposed to direct sunlight long enough to cause a temperature rise inside the tire. Double check the accuracy of your tire gauge every six months. Most tire dealer's shops have a "Master" tire gauge you can check your gauge against. I favor the use of a digital gauge that can be calibrated to atmospheric pressure before each use, but even these should be verified periodically.

TIP: When you pack your RV, do so with keeping it in balance in mind. And don't take more stuff (including water!) than you'll really need!

Always make sure your tire rim diameter and the rim/wheel diameter are identical. Whenever possible, use tires of the same pressure on an axle. Use the higher pressure when two tires are unequal, as over inflation is far better than under inflation. If you change to tires of a greater load capacity, you will be able to use a somewhat lower tire pressure.

Since in one form or another we RV'ers take our home with us, weight is a significant problem. Manufacturers try to build RV's to fill our every need and desire, but there is a problem! Most RV's are overweight. This weight causes premature equipment failure causing that dreaded highway breakdown, or to cause the driver to get out of control and cause an accident. GVWR (Gross Vehicle Weight Rate) is the maximum the design of the RV can weigh. GCWR (Gross Combined Weight Rate) is the maximum the design of the RV plus anything towed or carried can weigh. Many people think that manufacturers design into RV's a lot of over capacity, sometimes called a safety factor. They do not because that costs money and makes their product less competitive. If an accident happens, and the overweight of a vehicle is shown to be the cause, law enforcement write tickets, insurance companies don't pay claims, and lawyers start writing letters and filing law suits. Why take the risk of being overweight? It is dangerous. Don't let your ego get you into this kind of trouble by thinking: I never drive fast, my truck can handle any fifth wheel, I put an extra transmission cooler on my truck so I can tow more, etc. There is a new rationalization for each driver and each situation. If your equipment is not rated to do what you really want to do, then please find a way to get it matched up for safe and legal driving. If your truck is under rated for your fifth wheel, then either get a bigger truck or a smaller fifth wheel. If your motorhome is rated to tow 1500 lb. and your dingy weighs 3000 lb. then get a braking system for you dingy. RV'ers should do everything in our power to be responsible. Make sure your hitch is rated to tow your trailer, or your fifth wheel hitch is rated to tow your fifth wheel, etc.