One awful RV tire blowout disaster can ruin your entire day—or end your life. This motorhome driver was totally unprepared when tragedy struck:
Was there any way this driver could have avoided such a terrible RV tire blowout disaster?
Insight from tire experts like Michelin North America RV Tires would likely tell you “Definitely!” Losing control during a sudden loss of air, driving an overweight vehicle, expired tires, and being on the road with incorrect tire pressure are common causes for tire blowouts according to Michelin.
If an RV tire blowout happens to you, can you drive your RV to safety?
Did you guess the right answer?
If you didn’t answer “B,” your odds of dying in an RV tire disaster are exponentially high. Although driving faster seems illogical when all you want to do is stop the vehicle, experts tell us it will save your life.
The Michelin Tire safety pros in the video below say that hitting the gas and accelerating quickly with confidence will help you maintain control of your RV during a high-speed blowout.
Why speed doesn’t kill in RV tire blowouts
If your front RV tire suddenly loses air, the front corner of your rig will fall. That droop creates a sideways force that wants to pull your RV off the road, as demonstrated in the above RV wreck video. If a vehicle is traveling slowly during a tire blowout, the sideways forces gain strength and pull even harder to one side.
Going faster is the only one way to overcome those sideways forces. Moving at a higher speed lets you add power to the drive wheels. This extra juice enables a driver to conquer the side forces and get to a safe place.
It’s the same principle if you’re driving during high crosswinds. To get through it, your goal is to accelerate, keep a good grip on the wheel and drive in a steady, straight line until you can safely pull over and stop.
When sideways forces pull the vehicle because of an RV tire blowout, resist the urge to hit the brakes. Gradually speed up enough to travel in a straight line, then head to the nearest safe spot.
Front or rear, you deal with RV tire blowouts the same.
Front or back, RV tire blowouts are handled the same way
Whether your front or rear RV tire goes, both scenarios are handled exactly the same. The only real difference is how they feel. When a rear tire goes flat while you’re driving you’ll barely feel it in your seat. It’s also far easier to stay in control with two good front steering tires. But if a front RV tire loses air, it’s far more difficult to commandeer an unstable steering wheel.
RV tire blowout disasters are justifiably frightening. But as long as you keep a cool head and don’t panic, you can survive any situation. Here’s what the Michelin experts recommend:
Learn more about driving on safe tires
To avoid putting yourself into an RV tire blowout disaster in the first place, take time to learn about RV tire safety in these RV Life articles:
- Checking Tire Pressure
- Prevent Blowouts By Monitoring Your RV Tires
- Five Easy Ways To Maintain Your RV Tires This Season
Rene Agredano and her husband, Jim Nelson, became full-time RVers in 2007 and have been touring the country ever since. In her blog, Rene chronicles the ins and outs of the full-timing life and brings readers along to meet the fascinating people and amazing places they visit on the road. Her road trip adventures are chronicled in her blog at LiveWorkDream.com.
What you don’t mention is , what if there is a car in front of you? How can you speed up?
Great point David, thanks for bringing it up. That very situation happened to us when our rear trailer tire blew. We were in thick 65-70mph freeway traffic outside of Austin when my husband realized our tire was blown. He very, very gradually accelerated as much as it was safe to do so. There was only so much he could do in traffic, but he just kept a steady speed and a firm grip on the wheel until he found a break in traffic and pulled off to the right emergency lane. Does that answer your question? Hope you never need to use this kind of advice but thanks for reading.
Thank you much for your response. Hopefully this will never happen to us since we have the tire minder. Great video thanks for sharing. David with 2guysrving.com
Tire Minder will NOT warn you IF you hit a road obstacle and have immediate blow out….IT WILL TELL YOU AFTER, not until it blows.!! Best use is for pressure monitoring and heat build up. It is in those cases where it’s value is best.
You are not really adding speed to the vehicle. You are adding power to the drive wheels slightly which overtakes the sideways pull of the blown tire. You do the same thing fighting a sidewind automatically without thinking.
Even if you momentarily forget when it happens, you can regain control by accelerating as long as you don’t touch the brake.
I taught this method for over 25 years for a company, contracted by the tire industry to test competitor’s tires. Many, many blow-outs without a crash. 80+ vehicles running 24 hours a day for over 25 years.
Fantastic way of explaining it Nick, thanks!
I have had the great experience of losing one as well. You are accelerating but the rig will pretty much hold a steady speed with more throttle input. Just don’t make any crazy corrections, just steady pressure to stabilize the rig. An over correction or slamming on the brakes will definitely put it on its side…
While it is mentioned it is not said enough(BOTH HANDS ON THE WHEEL} not casually driving with one hand as it is also the (initall pull on steering wheel to one side or other that starts the sway.Also i also never use cruse as i want to do instantly as my reflexes allow what is needed to control my vehicle.
well its a motorhome and not likely to sprint ahead (mine would not lunge forward at any rate)
What isn’t mentioned is the fact he was going too fast. The truck filming is probably going the speed limit or faster, so this motorhome is going over 65 mph or faster and this may have contributed to the disaster as tires fail due to heating if pushed too fast under load or if over/under inflated. Food for thought. I hope the passengers/driver were not injured badly.
I discovered that the tires installed by the factory on my trailer are at their maximum load when the fully loaded trailer is standing still in my driveway. I then calculated that when I tow my trailer on a curve and the trailer leans on the outside tires, those tires are overloaded by 30% or more. I also calculated that a crosswind will do the same thing….cause overloading of the leeward tires. The solution is better tires and wheels than provided by the factory. A beefed up suspension might also be needed.
If motorhome tires are sized the same way, they’ll have the same problem. There will be repeated tire overloads as the motorhome is towed on curves or in a cross wind. I suspect this repeated overloading can ultimately lead to tire failure when the vehicle is otherwise properly loaded.
There needs to be a margin of 20% to 30% between combined load rating of tires and the GVWR of the vehicle (minus tongue weight in the case of a trailer).. This margin doesn’t exist on the trailers I’ve examined. I’d suspect it might not exist on motorhomes either.
motorhome is towed => motorhome is driven
sorry ’bout that!
I’m going to make a fairly confident but unprovable assumption that the margin for what you describe is already there. If the manufacture rating is 5000#, they would build the tire for 6000# and just not tell you. The problem with TELLING us is then some would load the tire sitting in your driveway to 6000# and feel it is safe when in all actuality as you described above it would be overloaded during certain situations.
So, I agree with you but assume it’s already there.
What makes you believe it isn’t?
I’m glad you asked that. This issue is driving me nuts!
I originally expected the same thing.
But after investigating it, I found out otherwise for my trailer.
I’m guessing that the same issue would apply to motorhomes, but haven’t done the math and the research. I’m raising the flag that I suspect the same problem exists.
Part of the problem is that RVs tend to be tall, so more so than cars, they are subject to large forces leaning on the outside tires on curves, and they have large cross sectional area so they are more vulnerable to side forces from wind. Cars won’t be as vulnerable to these forces compared to RVs.
I’ve investigated the DOT requirements for testing of trailer tires, specifically FVMSS-109. Tires are not tested beyond their load rating, period. There is no government requirement of a built-in safety margin. The testing agencies that test tires test them per FVMSS-109, so testing isn’t done during overload conditions. A given manufacturer could choose to make tires more robust than required, but he’d be at a competitive disadvantage for cost reasons. I’d be extremely surprised if the Chinese import tires have extra margin driven by the manufacturer.
I found absolutely no basis in the government specs to assume that trailer tires can take more than their load rating.
The underlying problem, for trailers at least, is that the DOT requirements are flawed. DOT allows tires to be installed on trailers so that the GVWR minus tongue weight equals the total tire load rating. This leaves no room for added forces when underway. The manufacturers of trailers seem to follow the DOT rules, without doing the additional engineering to look at what happens when the vehicle is moving. What the manufacturers miss in doing this is that product liability law in many or most states puts responsibility on the manufacturer to produce a safe product even if government rules are inadequate.
I’m really surprised that a lawsuit resulting from one of those roll over videos hasn’t pursued this issue and driven both DOT and the manufacturers to do better.
FVMSS => FMVSS
For the record Richard, I never said the tires were TESTED above their rating, I said they were BUILT above their ratings to ensure they passed that test.
However, I also am not as passionate about the topic as you obviously are based on your research.
What drives my passion is having had an unexplained blowout on a new trailer on Monarch Pass in Colorado, where there is no guard rail and a cliff at the edge of the road. I had been doing everything right.
When I did the math and physics on my trailer, I found that my tires were overloaded by almost 600lbs (30%) each time I took a turn at the posted advisory limit.
I could easily be dead because of a tire failure that very likely was preventable.
Carlisle Tire get it.
In their Tips & Best Practices document, they recommend that the “combined capacity of all the tires should exceed the loaded trailer weight by 20 percent”.
Because there is no mention of subtracting tongue weight from trailer weight, this amounts to a 30% margin between tire rating and static load.
http://www.carlstargroup.com/cms_files/original/Trailer_Tires__Tips_Best_Practices.pdf
Really!? This is an RV, produced by an industry that’s notorious for putting barely marginal equipment, especially tires and axles, on their products. Did anyone notice that there was a huge piece of garbage on the right shoulder, right where the tire blew? Sure looked to me to be a tire carcass and it wouldn’t surprise me that the MH hit another remnant that was enough to cause the blowout.
I do happen to agree that speed was very likely a factor in this, but I don’t necessarily agree with Michelin about tire conditions. As I said before, with the schlock mfrs. tend to put on their products, an “overloaded” tire, could likely be one that was OEM and just junk to begin with, and probably over-rated by at least 2 classes. A responsible RV owner will check his/her tires before every trip and at every stop, so the only other real way for a tire to go down is from a road hazard.
There are at least 2 instances I know of where spare tires on months-old fifth wheels blew out while sitting on the spare carrier, never having been on the ground since new. This, alone, tells you what kind of junk the mfrs. tend to use.
many many years ago I had a blow out in my car, cause……………………..crossplye tyre with a tube, I was told that was the problem, if the tyre had been a tubeless “radial” tyre it would not have happened.
What about if you tow a trailer? Do the same rules apply (i.e. accelerate to maintain control)?
Well it worked like a charm for us while towing our fifth-wheel and dealing with a blowout.
Thanks,
good to know. Glad you were safe.
This same thing happened today on Business I-85 in Spartanburg County (SC). The RV blew a tire and crossed the median, ending up travelling into the path of oncoming vehicles. There was no rollover, and remarkably no one was injured. WYFF-4 has video of the incident. Looks almost identical to this.
Link to WYFF4.com and their video of todays accident: http://bit.ly/2cY904Q
Thanks for the video. He just kept going the wrong way for what seemed like a long time. Wow, incredibly lucky.I’m sure the other Class A was thanking his lucky stars it wasn’t him.
Does nobody get it?
There are to many tire failures on RVs and trailers.
Why does everybody accept this without challenging the vehicle design????
What exactly do you expect people to do, stop buying RVs? We are aware that there are issues. As such, we always check inflation pressure and lug torque before starting a trip. We also plan on upgrading to higher load rated tires next year.
If you’re upgrading your tires, you’re taking a big step in the right direction, IMHO. However, you really shouldn’t have to do this. It’s the manufacturer who should have done it as part of the design.
My suggestion:
The best solution to surviving a blowout is to not have the blowout in the first place. A key part of this is making sure that the tires are rated to handle the loads they’ll experience not just when sitting still, but also when underway.
1. Weigh your fully loaded motorhome (weight at individual wheels is better but much more complex)
2. Add up the load ratings of the tires (on the sidewall of the tires)
3. Subtract 1 from 2
4. If the result is negative or less than 20% to 30% of 2, get better tires (you can also be suspicious that your wheels and suspension may also be over stressed when moving)
5. If you don’t have a TPMS, get one.
6. Complain to the DOT and to your manufacturer that there is inadequate margin in your factory tires to allow for the likely forces on them when underway.
Note that my 20% to 30% margin is based on my calculations on my trailer, and is similar to the recommendations from Carlisle tire. To get more precise requires doing complex math and physics on your vehicle, which will be beyond the reach of most owners, but which should have been done by the manufacturer.
In my case, I had to do a lot of shopping to find tires that would fit and also handle the dynamic loads on my trailer. Hopefully your problem can be solved simply by going from tires with a ‘C’ load rating to ones with a ‘D’ or ‘E’ (using the load rating classes for trailer tires).
There is no reason that RV owners should accept that it is their responsibility to properly size the tires for their vehicles. This is an engineering task that should be required of manufacturers by improved DOT regulations.
Oh, and do not under any condition allow the weight of your RV to exceed the GVWR on its rating plate. Better tires do not increase the GVWR.
When’s the last time you saw a bus with a blowout?
That RV’s seem to have a disproportionate number of tire failures is a symptom of something wrong.
I know manufacturers will point at RV owners, and RV owners may point at the tires.
My suspicion is that the manufacturers and DOT are probably at fault for installing and permitting tires that have no margin for dynamic forces that occur when under way.
If your tires are loaded to their maximum capacity when sitting still, they’ll be overloaded when you’re moving..
The RV industry is a cut throat maximum profit industry. The chassis are fabricated and the minimum needed tires are installed to deliver it to the RV manufacturer. Pretty much every trailer out there comes off the lot with minimum needed to meet the GVW. Having the tires at 90% capacity from the dealer is not uncommon.
Also, trailer tires are only rated to 65mph. I see so many posts in forums about pulling at 75-80 mph and when asked, they have no idea about the tires. Disasters waiting to happen.
Best thing anyone can do when getting a new trailer is check the tires and most likely, get them upgraded to a higher load class and higher speed rating. The bigger the difference between actual loading and actual capability the better in terms of heat and stress handling.
And another thing. Will owners please stop stating that regardless of the rating you can always do more than that. I see consistently that owners say that tow vehicles can tow way more than their ratings and tires can handle more than their ratings. I’m an senior engineer for a huge defense contractor. Let me tell you about ratings. When it says “Max weight=xxxx” or “Do not exceed….” It means just that. Can you go further? Sure. But the design and testing has shown that the ratings are the highest operating envelope before safety becomes compromised. Exceeding these means you are dramatically increasing the chances for catastrophic failure.
You want to exceed the ratings of your tires or tow capacity because “you think ratings are BS”, then you will end up rolled over in a ditch, too. Ask yourself right now: what’s my trailer weigh, what are my tires rated at, and what’s my margin? If you can’t answer this immediately, you WANT to get those answers ASAP. It could be the difference between life and death for you and your family.
I agree completely. I guess engineers think alike.
Your words about upgrading the tires are spot on.
This shouldn’t be necessary.
RV products should be safe as shipped, but the math and physics I’ve done for my trailer and a half dozen others says that they are not safe when fully loaded to the GVWR..
This is because the factory installed tires are not rated or tested for the dynamic loads they’ll see when underway, especially on curves and in crosswind..
Blowouts in cars are rare; in RVs they are not. Anytime we hear of a blowout in an RV alarm bells should be going off. Sure in some cases the owner may have done something wrong, but in my opinion there’s also a good likelihood that the root cause or partial cause is in the design of the RV itself, This is not something we should accept as customers of the RV industry, or as taxpayers who pay to fund the DOT.
The problem with engineers is that they focus solely on ONE issue and can’t get beyond that and think about common sense. If you think those tires are blowing just because they are overweight for a couple of seconds while the trailer is leaning, then that is your only focus. There are so many more factors involved in tire failure that you don’t seem to mention.
Speed, tire pressure, outside temperature, road conditions, how many times the dbaz behind the wheel hit a curb, cut a U-turn, jack knifed while back in, twisted the tires off of the rim, etc. All common sense items that people should know before hooking on to any trailer.
Sure, there are a host of other possible problems. This doesn’t do anything to soften the problem that tires installed on my trailer, and on a handful of trailers that I examined, aren’t rated for the loads they’ll see in normal usage.
The problem with engineers is maybe that they are more inclined to look for and prevent problems, than ignore them and hope for the best.
In my case, if I have another tire failure, it won’t be because the tire is under rated for the application, So I will be safer than I otherwise would have been.
Does accelerating, during a blowout, apply to to pulling a 5th wheel, too or just a motor home?
Hi Lisa. Yes it does. It worked like a charm for us while towing our fifth-wheel and dealing with a blowout.
Thank you, Rene! We’re newbies and just got our first 5th wheel, so this is good to know. Thanks again!
Notice how the blinker comes on right at the blow out. This could be bad luck or it could be his left hand was not on the wheel and he hits the blinker as his hand rises to grab the wheel. If he didn’t have both hands on the wheel when it blew out that could be a contributing factor. It looks to me that speed, even if it wasn’t over the limit was a contributing factor. He clearly didn’t have the skills to control for a blow out at his speed.
Okay, here’s the thing. In the case of the motorhome in the video, that was likely a quality tire. So about all you can do there is maybe blame poor inflation pressures. Who knows. But all of us with trailers know (or will know soon) that trailer tires are GARBAGE. They’re made in China and every one of them will explode eventually. Many will explode when only a year or two old (if even that old).
My 5th wheel toyhauler had all six tires delaminate on my first long trip. I replaced them with more of the same because that’s all I could get (except the replacements were at least load range E instead of D). All six of those eventually exploded, one of them doing $3500 damage to my trailer. I replaced those with another brand, hoping for better results. Of the new tires, three of them were on the verge of blowing when I noticed the bulges in them, and said enough is enough. I bought seven new wheels (16″ this time) and tires, and went with light truck tires. Haven’t had a problem since.
What I’m suggesting is that it’s time to get NHTSA or some other gov’t organization involved in these crap trailer tires. I’m surprised it hasn’t happened yet. But something needs to be done about them, because they’re a danger to the public in many ways.
I suspect speed was also a factor in the crash, rollover.
This is one of those rare cases where I will agree… but what I was saying is that tire quality is definitely an issue. Blowouts are far less of an issue on trailers than on steering axle of the tow vehicle or motorhome. When I’ve had blowouts on my big fifth wheel, I wouldn’t have known were it not for noticing the very different “pop” sound they made. The trailer didn’t feel any differently.
These huge motorhomes are constantly barrelling along not only well above the speed limit, but also well above the max rated speed of the tires. I’m surprised we don’t see more of this kjnd of thing.
Gee I haven’t noticed that. Having driven my motor home from coast to coast and border to border, I have not seen a lot of my kind passing me, and I rarely if ever go the speed limit, like to keep her at about 60 MPH since for every MPH over 60 you have to figure 2 cents per gallon increase in fuel usage (works out that way). Of course I have always driven gas powered RV’s my current RV has an 8.9L GM Gas burner, I pull a Jeep Liberty behind me and try to keep a close eye on her through my rear vision camera, when not in heavy traffic.
I experienced TWO blow-outs at once on my old Motor Home, the first tire took out the exhaust pipe, which ran under the tandem wheel and blew it out. Thankfully I had duels and tandem axles so there was till one tire holding my MH up. This happened on I-90 in Montana so traffic was not a major concern, I had just watched a video much like this one before our trip to Yellowstone so I did as the video said, (I was in the passing lane as there was a breakdown on the highway) and got control then pulled to the side. I nearly had to clean out my pants, and the wife wanted to know what the hell I was doing, but we made it OK. The 4 hour wait for the repair truck was the worst part, it was nearly 100 degrees, my generator died so I couldn’t run the roof air, and my brother in law was behind me sitting in his rig laughing his ass off at me. That said, we made it OK, I had just had the tires checked by a mechanic who repaired the brakes about 200 miles back, he said he had “aired up” my tires all around. Not sure what he aired them up to, but I had the roadside repair check, the tires on my rig recommended 65 pounds, and all the other tires were “aired up” to over 100 pounds. Perhaps that was the problem. The rig I have now has much larger (and way newer I must say) tires that require around that air pressure so perhaps the mechanic was used to working on larger tires???
Regarding an incorrect premise by Charles Rollman;
His conclusions (in quotes below), regarding that since his tire are “repeatedly, (if intermittently), “overloaded… i.e. when his vehicle is driving through a turn on a curve, etc.;
===============================
“Charles Rollman says
September 14, 2016 at 11:11 am
I discovered that the tires installed by the factory on my trailer are at their maximum load when the fully loaded trailer is standing still in my driveway. I then calculated that when I tow my trailer on a curve and the trailer leans on the outside tires, those tires are overloaded by 30% or more. I also calculated that a crosswind will do the same thing….cause overloading of the leeward tires. The solution is better tires and wheels than provided by the factory. A beefed up suspension might also be needed.
If motorhome tires are sized the same way, they’ll have the same problem. There will be repeated tire overloads as the motorhome is towed on curves or in a cross wind. I suspect this repeated overloading can ultimately lead to tire failure when the vehicle is otherwise properly loaded.”
==========================
The actual issue with ‘over-loaded’ tires is not that they are physically incapable of supporting the weight and might pop like sitting on a ballon, (even parked on a driveway)… but rather the actual issue is the ‘over-heating’ that occurs from the tir’e’s sidewalls ‘over flexing’ during extended driving, for many miles of continuous driving, (rolling). This excessive ‘flexing generates excessive heat’, which then causes the tire failure. Having your tire pressure set correctly, or even at it’s maximum listed tire pressure is the best guard against ‘over-flexing’ because it stiffens the sidewalls. Of course this does not mean that the correct tire size, and ply rating… and age… and condition are not equally important, they are. I am just clarifying that the short duration of vehicle leaning on curves, (thus momentarily shifting some weight to the one side etc. is not going to cause excessive heat build up which is the real issue in many blow-outs. Road hazard damage to the tire is the other frequent cause of blow-outs, (even months later). Just an FYI . . .
My experience the math and physics is with trailer tires. Trailer tires are tested and designed to meet FMVSS 109. There is no requirement that they exceed FMVSS109 in any way. FMVSS 109 does not require testing above 100% of load rating. So any forces on the tire in excess of load rating could cause a tire failure. If you assume the tire is safe above its load rating, you are gambling, pure and simple.
My failure was on a winding mountain highway, where each turn was followed by another turn with little time for the tires to cool. So it’s possible that heat build up triggered the failure. But short term overloads can also cause eventual tire failure, which is why tire manufacturers recommend replacing all tires on the same side when a failure occurs.
Cross wind can cause continuous overloading. You could drive all day on I70 with an overload of your leeward tires if there is a significant wind out of the south, for example. There is absolutely no reason in the engineering of the tires to expect them to survive unless the tires are rated for the load when underway.
Any argument that tires can safely exceed their load rating is wishful thinking, pure and simple.
BTW, if you want to believe that your tires will tolerate overloads when under way, you can do what I did….ask the manufacturer. The manufacturer of my tires told me that any loads that exceed the load rating can lead to failure that would not be covered by warranty. I specifically asked about overloading on curves.
There are all kinds of contributions to rollover caused by blown tires including DRIVER ERROR. Most people driving motorhomes do not have complete control due to improper steering wheel grips. A front tire blowout can be controlled completely if both hands are on the wheel at with the THUMBS UP on the wheel not wrapped around the wheel or the spokes. UPS tractor trailer drivers are taught this at the beginning of their training because if your hands are gripped with the thumbs wrapped around the wheel The sudden jerk caused by a front tire blowout will spin the wheel and can cause the spokes to break your thumbs and you will lose control. No group has a safer driving record than UPS Feeder drivers, the largest fleet in the world. Remember your motorhome is just a large truck with a big box on it and acts the same way as any other truck!
OK, I have read comments after comments on tire failure and what should be done to correct this situation and too meany reason they fail. We, my wife and I bought a new 1999 Dutch Star DP, in 2004 Newmar Co. contacted us telling us with advice telling us our coach front end was overloaded by the owners and that we needed to up-grade our tires to larger size, I’m no Rocket Science by no means but the light came on, I had a filling that the tires on our D Star was marginal before they even notified us.. But the NewMar Co. did put a foot in the door for what ever reason, the other up-grade a V=Plate was welded on the A-arm assembly, all I’m trying to say is the RV industry is not like they us to be. If the safety standard in tires go up be ready to pay the price, have you heard of no flat run tires, will this work on the front of MH’s.. Have a nice day
I also have had two blowouts. Both happened to the left front. One of them almost costs me my life. 12 inches from hitting a bridge. When I got home I researched Steer Safe. I immediately had one put on. I had a left front blowout years later. And it kept the motorhome safely straight. Best $400 I have ever spent. I would recommend it to all RV’ers.
Ditto: Had Steer Safe installed on our 37′ Holiday Rambler Class A at Camping World. Had a front tire blowout at 65 mph in Tennessee. No problem. Motorhome remained straight. Foot off the gas, Flashers on, Let it slow down and eased off to the side. Steer Safe was about $250.00. GREAT INVESTMENT. I highly recommend it for all large vehicles.
So why did your tire fail?
Wish I knew!!! No warning.
Something is wrong when experiences like yours seem commonplace while similar failures in cars are rare. Not many like to hear this, but I still believe that tires on many trailers, and probably motorhomes, are overloaded by design.
If it were mine, I’d weigh the vehicle, wheel by wheel if possible, and then compare the static load on the tires against the load rating on the side walls. If the load on the tires is close to their load rating when standing still, you can bet that when you’re leaning on a curve or driving in a cross wind the tires will be overloaded. Overloading can cause damage that progresses and accumulates over time, so it may not result in an immediate failure. For ST class tires, there is no built in margin to absorb this overloading; but for motorhome tires you may need to do some research to see if the same is true.
I’d then see if I can find tires with a significantly higher load rating.
My target is a 30% margin because my math says this is what it takes to make my trailer safe.
Such a large margin may be hard to achieve.
In my trailer I got the best tire I could find that would fit and picked up 23% margin when fully loaded to the GVWR.
The saving grace is that I don’t need to load to the GVWR.
I’d also complain loudly to the manufacturer.
Left side blowouts are a bit of a mystery. Right side blowouts I think are sometimes caused by right side tires being driven on the shoulder and hitting debris or driven over curbs. If you follow an RV or trailer in the city they will run over a curb, drive on the shoulder or hit the only pothole in the road.. Can’t explain it just a fact of life.
The advice of what to do in case of a tire failure on a large RV is helpful. However it might be better to take the steps needed to reduce the chances of having an unexpected failure if the first place. It would also be a good idea to understand the “why” of a tire failure so the corrective or preventive actions taken might actually help you.
Since I haven’t seen the front tire that caused the crash in the top video I can only guess at the cause. I can however point out that the picture of the failed tire is not a Run Low Flex Blowout but is in fact a belt separation and this mode of failure has a completely different cause and possible preventive action that a sidewall Run Low Flex Blowout.
Sidewall flex blowouts are caused by running a tire when it is loosing air pressure or is significantly low to start with. With Passenger, ST (trailer) type and most LT type tires that have Polyester body cord for the body, running at highway speed with a loss of 50% more of the required air pressure can result n significant heat being generated in the upper sidewall of a tire which can result in the body cord loosing half or more of its strength in just a few miles. In extreme cases the heat can even result in the Polyester cord melting and leaving tell tale evidence after the failure. This type of failure can usually be avoided by running a Tire Pressure Monitor System that will alert the driver of air loss and many times giving the driver advance warning so the driver can still pull over and make a safe stop. In the case of steel body tires as found on most Class-A RV and some Super-C the steel body cord does not melt but fatigues, just as a paper clip fatigues and brakes when bent back and forth a lot. It only takes a few miles for this type of failure to occur so even checking air at a campground is no guarantee of not having this type of failure just 5 to 50 miles down the road.
Belt or Tread separations usually develop over many hundred or even thousand miles. This can occur from a combination of high speed, high load, tire age and lower than optimal tire pressure. Since this type of failure takes many miles to develop there is often a warning in the form of localized rapid wear in one or more spots on a tire tread. To see this condition close inspection with both eye and hand feel for irregular wear. You can not normally do this with just a walk around the coach as probably two to three minutes per tire is needed and if nothing is found the coach would then need to be moved a bit to bring the portion of the tire that was on the ground up so it is available for inspection.. Ideally this type of inspection could be done from an inspection “pit” as seen at some oil change locations with the aid of a bright work light and a technician with a number of years experience in visual tire inspection. Even with this level of attention you can not be 100% sure of finding the problem before it becomes a tire failure but there is a good chance you could find the issue before it becomes real serious.
I have read most of the comments in this important series discussing tire failures. I have been in the tire business for just over 5o years now, (auto, RV & large truck tires). These comments made by Roger M are very correct and relevant to the subject… much more than focusing on the additional weight that momentarily affects one side of the vehicle while driving on a curved road. Those kinds of additional momentary loads are already calculated into the “Load ratings” that are designated on the sidewall of every tire and that have been carefully engineered and paired up with the particular vehicles GVW (Gross Vehicle Weight), including a very comfortable margin of safety. The primary variables to be concerned with are indeed: Correct Air Pressure, not exceeding the vehicles GVW, excessive speed for long periods of time, (particularly driving across the desert in hot temperatures), the excessive age of the tires, road hazard damage to the tire, (even if it occurred many, many miles ago, such as hitting a very bad deep pothole or object at high speed)… or improper repairs made to a tire. (Never attempt to repair a tire with damage or even a nail hole on the sidewall or shoulder area of the tire. (Too much heat is generated and accumulated in those areas of a tire).
Other that that of course it is possible, (though rare), for a tire to be vulnerable to a failure due a manufacturing defect. In that regard, the visual inspection, looking for signs of tread or belt separation that Roger M mentioned is a good idea.
Happy & Safe driving,
~ ERIC H
Robert,
Please show me where in FMVSS-109 there is a requirement or test that takes into account overloads beyond the load rating of the tire, even if brief. I have looked carefully at that spec, which applies to ST class tires, and see nothing that guarantees reliability when operated for any reason or cause above the load rating of the tire.
In my humble opinion the main issue or concern being addressed by the Load range or Load rating of a tire… is ‘heat’. Heat is the enemy of all tires, (excessive heat). Heat is generated by the flexing of the side wall as the tire rolls along under a load on the road. If the tire is over loaded, or under inflated, it ‘flexes’ even more than intended or calculated in the specifications of the particular tire in question. A higher load range tire is built stiffer, (either by using more plys, or by using a stronger cord when building the tire), to reduce the heat generating over-flexing of the side wall. This is why your air pressure is so very important. When a tire is under inflated it flexes much more than is should, thus raising the heat level to a point that the rubber & plys cannot withstand without a failure.
Another way of checking if your tires are over flexing or over heating, is, when you stop for fuel or lunch etc. , put your hand on each tire to check their respective heat levels. If one tire, or one wheel position seems much hotter that the others, there is reason for concern. However: DO NOT CHECK YOUR AIR PRESSURE WHEN YOUR TIRES ARE HOT, (as in driven more that a couple of miles), because it will give you a false air pressure reading. The desired air pressure is that which is measured at cold temperatures, (within reason). If you check your air pressure after being on the road for a while, and your tires were actually LOW on air pressure, the additional flexing will then have heated up your tires to the point of where the heat increases the air pressure. This could then cause you to want to lower the seemingly high air pressure, that was already too low to start with, making matters all the worse as you can hopefully see. Never reduce your air pressure due to checking the pressure of a hot tire.
No one advises having your tires over loaded. But if some circumstance should put you in that situation, the best countervailing move would be to be sure your cold tire pressure is set at the maximum PSI per the tire’s designation on the sidewall, (or even a little higher), in order to reduce the sidewall flexing as much as possible. The downside to being over-inflating is primarily comfort. The vehicle will transmit the road vibrations more and the ride will feel a little harsher. But to me this is preferable to an over flexing tire. Charles: As person concerned with the best and most accurate tire ratings & specifications from the manufactures, (manufactures of both tires and vehicles), who want their products to ‘ride’ smooth & soft… I would tend to be a bit more concerned that they might slightly understate the ideal air pressure in terms of achieving the highest load capacity within a load range…in order not to compromise their all important ‘ride’.
~ ERIC
Sorry that the balance of the important information that I wrote in the above comments was not included. I guess it went over the allowed number of words.