CHECK YOUR TIRE PRESSURE!

Originally Posted By: Astro14
Originally Posted By: mystere
I follow the old school method in maintaining tires: I inflate them to the maximum cold pressure posted on the tire sidewall.


That's not old school...that's just wrong...


I'm glad you got to it before I did. I couldn't believe what I was reading. As stated the tire pressure on the side of the tire is MAX meaning that is all the tire can safely sustain. What you SHOULD be going off of is the air pressure label that is conveniently located on the inside of the door. It should tell you what to run your tires at cold. I don't even know where you got this more air = cooler concept.
 
For those of you who are influenced by data.

Let's say you are designing a vehicle - and in the process of selecting tires, you come across the following options:

a) P205/70R15 at 35 psi = 1499# load carrying capacity. Max pressure on the sidewall = 44 psi.

b) P225/70R15 at 26 psi = 1521# load carrying capacity. Max pressure = 44 psi.

For practical purposes, these 2 tires and corresponding pressure result in the same load carrying capacity.

So why is the max pressure listed on the sidewall the correct pressure? Obviously it isn't.
 
"Max. Pressure" equals.....drumroll, please.....maximum tire inflation pressure. Otherwise it might have imprinted in the rubber, "Recommended Inflation Pressure" or "Required Inflation Pressure," which it doesn't. The imprint is essentially a safety warning, rather than a recommended or required setting. Same as a redline mark on a tach.
 
Maximum SAFE OPERATING pressure... you can inflate a tire to 50+ PSI and not blow on you... it's when you put on weight and use it is w hen the tire becomes unstable and blow. So, Max. Pressure on the sidewall = Max. SAFE pressure.

Max. Pressure label is intentional and is there to protect the consumer and the manufacturer.

Why would you intentionally fill a tire beyond the max. pressure rating on the sidewall?
 
nailtire.jpg


Wife's car picked this up. Routine "is it round" eyeballing caught it. Pre- TPMS era car. Tire was "known good" and never needed topping up, until it suddenly lost 7 lbs a day.
wink.gif


Went in at a good angle, too, check out the end where it wore.
 
Originally Posted By: accent2012
Maximum SAFE OPERATING pressure... you can inflate a tire to 50+ PSI and not blow on you... it's when you put on weight and use it is w hen the tire becomes unstable and blow. So, Max. Pressure on the sidewall = Max. SAFE pressure.

Max. Pressure label is intentional and is there to protect the consumer and the manufacturer.

Why would you intentionally fill a tire beyond the max. pressure rating on the sidewall?



I get scared when I put mine up to 40PSI as WAY too high but some pppl do that for extreme highway mileage. Just hope they never have to panic stop.

I usually get it to 36 cold 40 hot as an extreme high inflation. MOST tires I have found het 4PSI more when HOT.
 
I had new Yokohama Avid Ascend's installed today at DT and they set the rear passenger side pressure to 60psi! Needless to say I'll be having a conversation with the Manager tomorrow morning!

My TSX calls for 32/30 but I like to keep them at 36/34.
 
Originally Posted By: GearheadTool
Originally Posted By: accent2012
Maximum SAFE OPERATING pressure... you can inflate a tire to 50+ PSI and not blow on you... it's when you put on weight and use it is w hen the tire becomes unstable and blow. So, Max. Pressure on the sidewall = Max. SAFE pressure.

Max. Pressure label is intentional and is there to protect the consumer and the manufacturer.

Why would you intentionally fill a tire beyond the max. pressure rating on the sidewall?



I get scared when I put mine up to 40PSI as WAY too high but some pppl do that for extreme highway mileage. Just hope they never have to panic stop.

I usually get it to 36 cold 40 hot as an extreme high inflation. MOST tires I have found het 4PSI more when HOT.


You realize that some cars spec over 40 psi, right? My Saab and BMW come to mind, and both have superior stopping performance to most any car on the road.
 
UMM! Don't get high tyre pressures confused with braking performance. The best braking performance is when you use the recommended pressures in the worlds most under read book, the infamous and often lost, "Owners handbook".
The recommended pressures will vary with weight and max speed, but I can assure you that pumping up normal tyres from a recommended typical 30 psi to 40 psi will increase not decrease the required stopping distance.


Originally Posted By: JHZR2
Originally Posted By: GearheadTool
Originally Posted By: accent2012
Maximum SAFE OPERATING pressure... you can inflate a tire to 50+ PSI and not blow on you... it's when you put on weight and use it is w hen the tire becomes unstable and blow. So, Max. Pressure on the sidewall = Max. SAFE pressure.

Max. Pressure label is intentional and is there to protect the consumer and the manufacturer.

Why would you intentionally fill a tire beyond the max. pressure rating on the sidewall?



I get scared when I put mine up to 40PSI as WAY too high but some pppl do that for extreme highway mileage. Just hope they never have to panic stop.

I usually get it to 36 cold 40 hot as an extreme high inflation. MOST tires I have found het 4PSI more when HOT.


You realize that some cars spec over 40 psi, right? My Saab and BMW come to mind, and both have superior stopping performance to most any car on the road.
 
I just got:

Accutire digital tire pressure gauge,
VIAIR 85P Portable Air Compressor, and a
Roadpro 12V Battery Clip-On and Cigarette Lighter Adapter
smile.gif


(didn't want to risk any blown fuses of cig lighter sockets, so with that last gadget I can hook up the compressor directly to the battery - works great)

Now all I want to do is check tire pressures...
smile.gif
I should have done this years ago.
 
I run my PSI so it's close to 50 when the tires are warm. I've done it in all my cars and have for years now. The max rated has always been above 50. It Improves MPG tremendously and wet performance.

Go on Ecomodder.com and some of you will have heart attacks when you see how common this is, and with no failures. The max rated PSI is there and like other ratings leaves a safety margin. To think tires will just explode filled below what the manufacturer says they're capable of holding isn't logical.

I know a woman filled her tires up all the way around and drove on it for a couple months before she complained that the car was riding funny since she put air in all her tires. The highest tire was 91psi and the lowest was 88.
 
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^^^I sure hope you are never in an accident and found at fault. A sharp attorney will cut you up for dinner like a prime steak!

The facts are indeed true that a tire will not explode even at considerably higher than rated pressures. We used to run bias ply tires at 60 psi during autocross events in the 60's.

But the hyper mile club is endangering themselves and others with this practice, as it dramatically affects the performance envelope of the car, especially in an emergency.
 
Originally Posted By: JHZR2
Originally Posted By: GearheadTool
Originally Posted By: accent2012
Maximum SAFE OPERATING pressure... you can inflate a tire to 50+ PSI and not blow on you... it's when you put on weight and use it is w hen the tire becomes unstable and blow. So, Max. Pressure on the sidewall = Max. SAFE pressure.

Max. Pressure label is intentional and is there to protect the consumer and the manufacturer.

Why would you intentionally fill a tire beyond the max. pressure rating on the sidewall?



I get scared when I put mine up to 40PSI as WAY too high but some pppl do that for extreme highway mileage. Just hope they never have to panic stop.

I usually get it to 36 cold 40 hot as an extreme high inflation. MOST tires I have found het 4PSI more when HOT.


You realize that some cars spec over 40 psi, right? My Saab and BMW come to mind, and both have superior stopping performance to most any car on the road.


I don't doubt that, just that that would be a first (for me.) I still have the tires at ~30-32PSI on the Volvo. Debating changing that to 33 all around...

I also had a BMW at one point, albeit much older than yours. I remember inflating to 36PSI cold as "wow, high" but for best fuel economy.. had concerns about overinflating. Bridgestone Potenza tires, I think.

I have also found just about every tire I have ever had to gain 4PSI hot, with the exception of a cheap General tire that inflated 5PSI once, though that was after a long day of extreme speed complete with a skidding stop. (Wild days.)
 
Originally Posted By: Shark
........Go on Ecomodder.com and some of you will have heart attacks when you see how common this is, and with no failures........


I have been tracking this for a few years - mainly because I was told to put up or shut-up - that there were NO!! downsides and NOBODY had any issues whatsoever.

What I found was just the opposite. I have page after page of remarks that folks have made about issues with elevated inflation pressures from the very websites where no issues were claimed.

The fact is that there have been failures and there have been traction issues. It just difficult to assign this where it needs to be - because the guy analyzing the failure has confirmation bias.
 
Originally Posted By: GearheadTool
Originally Posted By: JHZR2
Originally Posted By: GearheadTool
Originally Posted By: accent2012
Maximum SAFE OPERATING pressure... you can inflate a tire to 50+ PSI and not blow on you... it's when you put on weight and use it is w hen the tire becomes unstable and blow. So, Max. Pressure on the sidewall = Max. SAFE pressure.

Max. Pressure label is intentional and is there to protect the consumer and the manufacturer.

Why would you intentionally fill a tire beyond the max. pressure rating on the sidewall?



I get scared when I put mine up to 40PSI as WAY too high but some pppl do that for extreme highway mileage. Just hope they never have to panic stop.

I usually get it to 36 cold 40 hot as an extreme high inflation. MOST tires I have found het 4PSI more when HOT.


You realize that some cars spec over 40 psi, right? My Saab and BMW come to mind, and both have superior stopping performance to most any car on the road.


I don't doubt that, just that that would be a first (for me.) I still have the tires at ~30-32PSI on the Volvo. Debating changing that to 33 all around...

I also had a BMW at one point, albeit much older than yours. I remember inflating to 36PSI cold as "wow, high" but for best fuel economy.. had concerns about overinflating. Bridgestone Potenza tires, I think.

I have also found just about every tire I have ever had to gain 4PSI hot, with the exception of a cheap General tire that inflated 5PSI once, though that was after a long day of extreme speed complete with a skidding stop. (Wild days.)


Here's a novel idea, check the placard on the Volvo for the correct pressure, and use that.
 
For the two Toyotas I go about 2 lbs over the recommendation on the door jam. The justification is that tires tend to lose air not gain it so there is a small margin. For the Volvo I go 1/2 to 1 lb above because 2 lbs over the 35 lbs recommended makes it ride like a buckboard.
 
Here's a novel idea. Get your vehicle weighed. Front axle first then both axles. Then see what the tire manufacturer whose tires you are running recommends and use that pressure.
 
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