Couple of psi lower tire pressure on the long road trips?

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Yesterday, while coming back after a long weekend, I noticed at least 4 cars with tire blowouts. The first time in my life saw 16-wheeler tire blow out. It was not even that hot yesterday. That made me wonder if one should reduce the tire pressure a couple of psi if you are going on a long road trip.

I am pretty sure the tires get hot on a long drive but I always thought that the tires are made to handle that heat. I admit I don't know the physics of it in relation to the tires.

Is there any consensus on how it should be dealt with in summer, stick to the pressure indicated on the door or reduce a bit? We usually take 15 min stops every 2 hours, but this year we are planning first long (~1200 miles) road trip, thought I should know.
 
More PSI=less sidewall flex, which is a leading cause of blowouts. As long as you have decent tires, I would run them at least what's recommended on the placard, they can handle some expansion due to heat.
 
Big rigs commonly run re-capped tires on their rear tandems and trailer wheels. Recaps blow out with regularity. Recaps are not allowed on the front axle of commercial vehicles. Aftermarket large diameter wheels with extreme low profile tires are others that have a high blowout probability. If your tires and wheels are to OE specs, are in good shape and filled to the posted air pressure, the probability of a blowout is reduced greatly. There is a lot of debris in the roadways that can be picked up and cause any tire to blow. Too many variables out there.
Just run the manufacturer recommended air pressure and make sure your tires are in good shape.
 
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With most modern tires the max PSI ratings have gone from 32 or 36 PSI to the high 40s and 52 on all the mid to high performance tires used on even the simplest cars. Most side piller tire rating on the car are in the 28 to 32 range and in a lot of the cases do not create a well "handling" car. Tire sidewall roll-over is higher and creates sidewall heat. Going from a cold tire to a hot one on average PSI increases 3-4 PSI. I run my tires at 40 PSI iand gain to 43 PSI after running them in my lowered and rimmed 2018 Hyundai Kona AWD 1.6T since I throw my car into corners hard and even at those PSI, I wear my tire evenly. These tire blow outs you see are more so because of lack of inflation pressure or just old bad cheap china tires. I saw this as a tire installer repair guy in a high end tire store in my youth for 4 years. So NO high PSI does not cause blow-outs. There is PLENTY of buffer zone built into tires even if you use the max rating on the sidewall and gain the 3-4 PSI. Under inflation and a heavy vehicles are HARD on tires and cause blow-outs. I myself don't like the manufactures rating on the side piller. I think it is under infating the tire and leaves no buffer zone if there is a small leak or you lose air with all tires with time. I like to see any tire that is rated for 52 like most to be at 36 and the 36 tires to be 35 PSI. The side pillar rating in my opinion are for a smooth mussy ride for gandpa and grandma. Not for the soccer mom hauling kids around and darting around shopping.
 
The blowouts that you saw were more likely caused by the atrocious road conditions in our area.
NY has been terrible with road maintenance in the last several years.
 
"Gators" remaining an obstacle to dodge … Follow what PSI is on the door pillar or glove box …
Heck, I don't even air down for sand … I buy 4WD vehicles with gear lockers and bump up the radials a size or so
 
No, not less PSI for long trips!
smile.gif


Keep in mind that the COLD tire pressure first thing in the morning is designed to take into account your daily commute and long trips.

What to do with extra loads is listed in the owner's manual. More weight in the vehicle necessitates more tire PSI. Also, more air(within specification) will allow the tire to run cooler and less air will cause the tire to run hotter. How much cooler or hotter, IDK! Keep at least the recommended PSI.
 
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I made 2400+ mile round trip to Oklahoma back in May, and other than checking them, I never touched the tires. They were all at 42 psi (max 44 psi) where I usually run them.
 
Originally Posted by MoneyJohn
Is there any consensus on how it should be dealt with in summer, stick to the pressure indicated on the door or reduce a bit? We usually take 15 min stops every 2 hours, but this year we are planning first long (~1200 miles) road trip, thought I should know.

No, not reducing but increase if need be.
Anything between readings on door pillar and MAX on tire sidewall.

Refer below quote .....

Originally Posted by Mainia
With most modern tires the max PSI ratings have gone from 32 or 36 PSI to the high 40s and 52 on all the mid to high performance tires used on even the simplest cars. Most side piller tire rating on the car are in the 28 to 32 range and in a lot of the cases do not create a well "handling" car. Tire sidewall roll-over is higher and creates sidewall heat. Going from a cold tire to a hot one on average PSI increases 3-4 PSI. I run my tires at 40 PSI iand gain to 43 PSI after running them in my lowered and rimmed 2018 Hyundai Kona AWD 1.6T since I throw my car into corners hard and even at those PSI, I wear my tire evenly. These tire blow outs you see are more so because of lack of inflation pressure or just old bad cheap china tires. I saw this as a tire installer repair guy in a high end tire store in my youth for 4 years. So NO high PSI does not cause blow-outs. There is PLENTY of buffer zone built into tires even if you use the max rating on the sidewall and gain the 3-4 PSI. Under inflation and a heavy vehicles are HARD on tires and cause blow-outs. I myself don't like the manufactures rating on the side piller. I think it is under infating the tire and leaves no buffer zone if there is a small leak or you lose air with all tires with time. I like to see any tire that is rated for 52 like most to be at 36 and the 36 tires to be 35 PSI. The side pillar rating in my opinion are for a smooth mussy ride for gandpa and grandma. Not for the soccer mom hauling kids around and darting around shopping.
 
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My experience with big rigs is tires mostly blow out due to low pressures.
Been to B/S test track in Texas for tire training, and oversaw a fleet of 100 tractors.
Hitting that blade at 60 mph to cause a blowout is ummm... interesting while in the cab.

Under inflation was our biggest concern.
 
Truck tires get a flat, get very hot and then blow out. They have automatic inflators on many trucks now to prevent that so is much more rare these days. You see them on the hub with hoses to the fill valve. Great deal. Saves a lot of truck tires.Essential with the super single tires.

When riding the MC if I smell hot rubber I give the truck a very wide berth or just t hang well back and watch for flying rubber. Having seen rubber cover the 2 inside lanes of a 3 lane highway, I do not think there is a motorcycle safe way to pass. If I do pass, I pass a quickly as possible. And car drivers are so erratic, you have to hang well back, like a 1/2 mile..

Rod
 
Originally Posted by RDY4WAR
I made 2400+ mile round trip to Oklahoma back in May, and other than checking them, I never touched the tires. They were all at 42 psi (max 44 psi) where I usually run them.


Isn't 44 psi the MAX on the tire sidewall or are these truck tires that require higher PSI?
 
Originally Posted by Char Baby
Originally Posted by RDY4WAR
I made 2400+ mile round trip to Oklahoma back in May, and other than checking them, I never touched the tires. They were all at 42 psi (max 44 psi) where I usually run them.


Isn't 44 psi the MAX on the tire sidewall or are these truck tires that require higher PSI?


44 psi is the max pressure on the sidewall. I've run 42 psi in these tires since new. They now have 41,000 miles on them and have no abnormal wear patterns. The vehicle rides smooth and handles well.

On that trip, I did check the tire pressure once on the way back after about a 4 hour straight run at 75 mph between fuel stops. I checked them while refueling and they they were all 43.0-43.5 psi so <1.5 psi pressure increase.
 
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I suspect the blowouts that you saw followed your way of reasoning: less air the better in hot weather.
I think they were caused by underinflated tires running hot and not overinflated tires rupturing due to the pressure.

Or debris killed them.

Just my opinion.

KrzyÅ›
 
I have a good friend up in Canada who drives a truck delivering liquid nitrogen all over North America. He said they never want to see the rear tires go below 80 psi as that is a danger zone for a blowout. The sidewall flexes too much which generates internal friction and warping which can cause the tire to blowout. He said he aims for 95 psi in rear tires and 110 psi in front tires with a range of 85-100 psi for rear and 100-115 psi for front. However, he said you will never get an accurate reading on a gauge with hot tires. He carries a sledgehammer in the cab and when he stops, he bangs the tires with the hammer. If the tire is low on pressure, it'll make a dull sound. If it's overinflated, it'll make a ping-like sound. He will then verify it with a gauge and/or let a little out and bang again.

He said the most calls his company gets from drivers with blown tires is people going from sea level to high elevation. As the ambient pressure decreases, tire pressure increases (relatively), and increases the chance of over-inflation and a blowout if the pressure isn't dropped accordingly.
 
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Originally Posted by RDY4WAR
I have a good friend up in Canada who drives a truck delivering liquid nitrogen all over North America. He said they never want to see the rear tires go below 80 psi as that is a danger zone for a blowout. The sidewall flexes too much which generates internal friction and warping which can cause the tire to blowout. He said he aims for 95 psi in rear tires and 110 psi in front tires with a range of 85-100 psi for rear and 100-115 psi for front. However, he said you will never get an accurate reading on a gauge with hot tires. He carries a sledgehammer in the cab and when he stops, he bangs the tires with the hammer. If the tire is low on pressure, it'll make a dull sound. If it's overinflated, it'll make a ping-like sound. He will then verify it with a gauge and/or let a little out and bang again.

He said the most calls his company gets from drivers with blown tires is people going from sea level to high elevation. As the ambient pressure decreases, tire pressure increases (relatively), and increases the chance of over-inflation and a blowout if the pressure isn't dropped accordingly.

If the 3 or so PSI difference between a high and a lower altitude is causing tire failure then there's something else going on.

Maybe his sledge hammer method of determining tire pressure reflects his skill in other areas.
 
Originally Posted by kschachn

If the 3 or so PSI difference between a high and a lower altitude is causing tire failure then there's something else going on.

Maybe his sledge hammer method of determining tire pressure reflects his skill in other areas.


He's been doing it for 40 years. I'm just sharing what he said on the topic. I'm not a trucker.
 
Originally Posted by bullwinkle
More PSI=less sidewall flex, which is a leading cause of blowouts. .

Under-inflation, not over-inflation, is the leading cause of blowouts.
 
Originally Posted by MoneyJohn
Is there any consensus on how it should be dealt with in summer, stick to the pressure indicated on the door or reduce a bit?

Never reduce the pressure from what is indicated on the door placard. If anything, some manufacturers recommend increasing the pressure a little bit for extended hwy driving. Higher pressures reduce heat buildup because there is a bit less sidewall flex.

https://www.aaa.com/autorepair/articles/the-importance-of-proper-tire-inflation
 
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