Archives

I drove to work on Tuesday and when I went out to my car during my lunch hour, I noticed I had a flat.

I took it to the tire shop and they showed me the tear in the sidewall and his theory was that it was caused by hitting a pothole. The weird thing was the road I traveled to work doesn't have any significant potholes, although there are quite a few small ones developing. I definitely didn't remember hitting anything on the way to work that morning.

I normally keep my tires just a little below the tire max of 51 p.s.i.

Was I more likely to have this happen due to keeping the tires inflated close to the max?

Maybe this was a fluke thing, but any money I saved from higher mpg's just went out the door in the form of a $120 new tire.

If 51 psi is printed on the sidewall of that tire, then that tire likely failed for a reason other than tire pressure. The burst pressure of a tire is at least 4-5 times that printed on the tire for obvious safety reasons. SEVERAL of us (myself included) have hundreds of thousands of miles on tires at or above sidewall indicated PSI without blowouts. You may have hit something that damaged the sidewall and not known it.

Do you have pictures? What is the brand, model, and age of the tire? What is the vehicle the tire was mounted on? Was the tear on the inner or outer sidewall? Any other information you can give to help determine a cause? I'm not saying it's not possible your PSI caused or contributed to the flat, but it is highly unlikely unless the tire was damaged/poorly manufactured.

Do you have pictures? What is the brand, model, and age of the tire? What is the vehicle the tire was mounted on? Was the tear on the inner or outer sidewall? Any other information you can give to help determine a cause? I'm not saying it's not possible your PSI caused or contributed to the flat, but it is highly unlikely unless the tire was damaged/poorly manufactured.

I don't have any pictures.
Goodyear Eagle RS-A's original tires that came new on vehicle (1 1/2 yrs old) 13,500 miles
2010 Pontiac Vibe
The tear was on the inside sidewall.

The only other fact that I didn't mention is that I normally tried to keep the tires at 49 psi but it had been a month or so since I had last checked them. When I checked them today, they were at closer to 41 psi. Also, in Northern Indiana it was below zero last week and was closer to the mid 50's when the incident happened less then a week later.

Can drastic change in temperatures put additional stress on tires?
Can tires stretch out a bit if I normally keep them at max and then when I was closer to 40 the sidewalls had more give and it compressed enough to pop the sidewall of the tire?

It could have been prior damage.

I blew one out a couple of years ago when I grazed a curb at 55 mph. It had a slice in the outside sidewall. 41 or 51 psi is not going to blow out a tire. I know at least one (personally ;) that has tried at least 2 (or more) times that psi with no ill effect.

OK, let me ask a different question.

Are you more likely to have a blowout if you hit a pothole with tires maxed out as opposed to what is normally suggested on the vehicle door?

Higher pressures are easier on the tire, but harder on suspension components and driver teeth. From what I've read around here.

Was there a puncture in the tire too? Sidewall blow outs are one of the failure modes when you drive on a tire that has really low pressure. You could've picked up a nail in your tire as you left home...

Hi ABC2Miller:

Higher pressures are less likely to cause a blowout vs. placard when you hit a pot hole or the worst condition of all which is placard and the minute you drive off, you are underinflated until the next check 2 to 12-months later.

Wayne

My son has worked at a service store (since Aug/2007) who's main focus is tires. He has noticed that people who run higher pressures are not only less likely to blow a tire on a pothole, it also seems to protect wheels/rims from damage.

Tire defect!!!! H

My son has worked at a service store (since Aug/2007) who's main focus is tires. He has noticed that people who run higher pressures are not only less likely to blow a tire on a pothole, it also seems to protect wheels/rims from damage.

That makes me feel better. With all the ice we got a few weeks ago and the cities not being able to clear the roads we have pot holes as wide as the lanes. Sometimes I am paying so much attention to the traffic and lights that I don't even see the pot holes until I hit them.

Higher pressures are easier on the tire, but harder on suspension components and driver teeth. From what I've read around here.

How serious is it on the suspension components? Say 44 psi vs. 35 psi (placard)?

How serious is it on the suspension components? Say 44 psi vs. 35 psi (placard)?

I guess that is a good question... as anyone here had to replace springs/shocks/struts sooner than they would have otherwise anticipated? I know I haven't, but I've only been running at or above MTP for a couple of years, about 35k miles maybe? My Kia only has 85k miles right now, and the suspension seems fine.

I guess that is a good question... as anyone here had to replace springs/shocks/struts sooner than they would have otherwise anticipated?

Probably too hard to answer, there are too many variables. In theory, we know that the suspension is doing more work because the tires aren't absorbing as much, but I just can't see it making that much difference on a practical level.

Keith

I think one needs to match their driving with their chosen tire pressure. If you drive like a teenager (no offense) over rough terrain, back off the psi a bit. If you cannot pass xcel, then high psi are fine. Besides the suspension, you should consider any rattles that might be worsened with the higher psi. I go slow with sidewall max, and have not noticed any abnormal wear. NVH is greater, for sure. YMMV.

This topic reminded me that my car has been making some noises from the shocks. So, I did a quick google search on how to check them.

I came across this after a few clicks:
How to Drive With Bad Shocks (http://www.ehow.com/how_6930960_drive-bad-shocks.html)
Note in particular tip #2.

Got me to thinking, driving at a slower speed means you are less likely to be affected by changes in the road. I asked myself, why that would be? Then I came up with this; wouldn't a lower speed in itself decrease the forces involved? And, if so do our lower speeds off-set the increased pressure in regards to wear and tear on the suspension?

If you cannot pass xcel, then high psi are fine.

That reminds me of when I ended up leaving a MiHG meet just after xcel. The route I took as a coincidence ran right through his home town. He was able to pull out of the parking lot before me so he had about a 20-30 second head start. I never saw him again. :D

Thanks everyone for the quick reply! :)

The Prius suspension is durable. Our 08 has been at 60psi since it left the lot and it as about 36K miles on it with no issues. The 10 has been at 60+psi since it left the lot and the only rattle is "the junk in the trunk" that my wife leaves in there. We will hit 40k miles on it in the next week or so.

BTW: How many Prius make it to 40,000 miles on the oem tires? Both of ours are oem and will make it to 60,000 easily.

If the tires are rated at 51psi it's not from too much pressure. As a matter of fact under inflation will do more damage to the sidewall than over inflation. I consistently run 45-50 psi on one of my cars that has tires rated at 35 psi and haven't had any problems except a stiffer ride. Actually the car handles better and the tires last longer with the tires over inflated. Years ago (pre '70's) when bias ply tires were all you could get running them at higher pressure would wear the center of the tire out before the edges, but radial tires run flatter on the road and you'd have to have extreme pressure to cause premature center wear.

The Prius suspension is durable. Our 08 has been at 60psi since it left the lot and it as about 36K miles on it with no issues. The 10 has been at 60+psi since it left the lot and the only rattle is "the junk in the trunk" that my wife leaves in there. We will hit 40k miles on it in the next week or so.

BTW: How many Prius make it to 40,000 miles on the oem tires? Both of ours are oem and will make it to 60,000 easily.

I have 50K+ on my Prius and have never had less than 60psi in the tires and have had 80psi+ for the last 2 years on my Ecopia tires with no suspension problems.

The Prius suspension is durable. Our 08 has been at 60psi since it left the lot and it as about 36K miles on it with no issues. The 10 has been at 60+psi since it left the lot and the only rattle is "the junk in the trunk" that my wife leaves in there. We will hit 40k miles on it in the next week or so.

BTW: How many Prius make it to 40,000 miles on the oem tires? Both of ours are oem and will make it to 60,000 easily.

Do I understand it correctly that you run the Prius OEM tires at 60 psi even though they are rated at 44 psi max?

Yes, That is true. One set is 51 psi rated though.

I have 35,000 miles on these michelins, running 60+ on a 44-rated tire. As far as I can tell, my suspension is fine at 184,000 miles. Sure, I have squeaks and rattles, but it's an old car. There's no knowing how much, if any, came from the higher pressure.

I have run 60 PSI in the Primewells on my car. They are rated for 36.

I have since dropped them to 50 for the sake of the wife since her car is getting junked.

Hi Ksstathead:
I think one needs to match their driving with their chosen tire pressure... If you cannot pass xcel, then high psi are fine.
If you are to that point, 100 + and as hard as a train’s steel wheels would suffice :D

In all actuality, I miss as many rough patches, holes, rises, ridges and debris as I can but its not because of damage, it is because of FE. If you spot something up ahead, slowly and I mean ever so slightly nudge the wheel to avoid it and do the same to get into your track after the impediment is passed. In the case of an emergency, slam on the binders, run through any pot hole or whatever and steer like you are attempting to miss a child in the roadway.

Wayne

Remember, though: "Stomp, stay, and steer" only works in ABS-equipped cars! If you have an old car like mine without antilock brakes, you cannot turn the car when braking hard!

I would also be more aggressive about avoiding a human in the roadway than a pothole. Damage to the car, while heartbreaking, is repairable. Damage to a person is much less so.

-soD