Tire Pressure

On the yokohama it mentions max 44 so any level under that is fine ?

What i do not understand is why the dealer always adds more then the recommended tire pressure .

I wouldn't say it's fine (and I don't mean to imply that). It is safe from an specification standpoint, that's all.

This is just a guess, but I think your dealer might be trying to compensate for a non-cold tire condition when you drive it in (as said before by others, cold tire pressure setting is best) and not getting it quite right. But IMHO it's better to be slightly over-inflated than under-inflated.
 
On the yokohama it mentions max 44 so any level under that is fine ?

What i do not understand is why the dealer always adds more then the recommended tire pressure .

I think to say that is over simplifying it. You should not exceed that pressure as that is the max the tire is designed to handle.

The recommendation from the manufacturer is specific to that vehicle for a tire of that size.

As to why the dealer is setting it higher. I experienced it a lot myself and usually notice right away because the car feels noticeably different to me usually not in a good way. My theory with the VW was I had a Rabbit but the techs just going with what the recommendation was on the GTI. With the Mazda maybe they over compensate for the tires being warm, inaccurate gauge, assumed you would ignore it till your next service. *shrug*

And I guess that’s sort of the point of why I’m refuting the guy who is advocating for running higher pressure. There certainly are reasons to to run higher pressure and he listed several of them. But there are drawbacks to doing so as well. And it’s not necessarily safer especially if you go to high like just running max. You should probably google it and maybe look at some of the articles on the Tire Rack on the topic to help understand and it won’t just be stuff some guy on the internet said.
 
Today it seems that to get external links to work you have to look for a another link on the "weird website" (in this case for me it was left center) that says continue to tirerack.com and had the tirerack logo (if you don't see it, scroll down).

One very important piece of info on the linked tirerack page is all the way at the bottom:

Maximum load inflation pressure (for testing purposes) on modern tires is defined at 35/36 psi which is a standard from the Tire & Rim Assoc. (in USA) or the European Tyre and Rim Technical Organization (ETRTO). You can safely inflate your tires beyond this to 44 or 51 psi (depending what your sidewall says), but it does not mean that it is only at that 44 or 51 psi that you get the rated maximum load capacity.

If you do carry heavy loads or tow a trailer (or travel at high speeds), by all means increase you air pressure. Not because of the load rating standpoint but to help the tire retain a more round shape and reduce heat build up.
If the rated maximum load is reached at 35/36 psi, (one person in a previous similar debate says at 32 psi), why we need to add more air pressure to carry heavier load as all tire pressure recommendations specify 41/42 such as Mazda CX-5, or 44 psi such as VW Passat from 34/36 or 30 psi when you have full load, as 34/35 psi has already reached maximum capacity of rated load of tires which is way over the actual vehicle weight for each tire needs to carry?

And how do you explain some tires state the following on the sidewall such as this tire used previously on my Honda CR-V:

YOKOHAMA AVID TRZ P205/70R15 95T
MAX. LOAD 680 kg [1499 lbs] AT 300 kpa [44 psi] MAX. PRESS.


Any person knows physics will tell your more air pressure will carry more weight / load, the upward curve can't be stopped at any air pressure going up until the tire blows up! :)
 
I think to say that is over simplifying it. You should not exceed that pressure as that is the max the tire is designed to handle.

The recommendation from the manufacturer is specific to that vehicle for a tire of that size.

As to why the dealer is setting it higher. I experienced it a lot myself and usually notice right away because the car feels noticeably different to me usually not in a good way. My theory with the VW was I had a Rabbit but the techs just going with what the recommendation was on the GTI. With the Mazda maybe they over compensate for the tires being warm, inaccurate gauge, assumed you would ignore it till your next service. *shrug*

And I guess that’s sort of the point of why I’m refuting the guy who is advocating for running higher pressure. There certainly are reasons to to run higher pressure and he listed several of them. But there are drawbacks to doing so as well. And it’s not necessarily safer especially if you go to high like just running max. You should probably google it and maybe look at some of the articles on the Tire Rack on the topic to help understand and it won’t just be stuff some guy on the internet said.
The tech advisor also mentioned that even having the car parked for many hours on a warm day will cause the pressure to rise inside the tire .

It seems that the dealer have there structure in place ,when i first picked up the car in october first thing i noticed was that the engine coolant was very low and they confirmed that it was at the level mazda requests .
 
If the rated maximum load is reached at 35/36 psi, (one person in a previous similar debate says at 32 psi), why we need to add more air pressure to carry heavier load as all tire pressure recommendations specify 41/42 such as Mazda CX-5, or 44 psi such as VW Passat from 34/36 or 30 psi when you have full load, as 34/35 psi has already reached maximum capacity of rated load of tires which is way over the actual vehicle weight for each tire needs to carry?

And how do you explain some tires state the following on the sidewall such as this tire used previously on my Honda CR-V:

YOKOHAMA AVID TRZ P205/70R15 95T
MAX. LOAD 680 kg [1499 lbs] AT 300 kpa [44 psi] MAX. PRESS.


Any person knows physics will tell your more air pressure will carry more weight / load, the upward curve can't be stopped at any air pressure going up until the tire blows up! :)

Edit: I give up and am unsubscribing. Just google it.
 
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If the rated maximum load is reached at 35/36 psi, (one person in a previous similar debate says at 32 psi), why we need to add more air pressure to carry heavier load as all tire pressure recommendations specify 41/42 such as Mazda CX-5, or 44 psi such as VW Passat from 34/36 or 30 psi when you have full load, as 34/35 psi has already reached maximum capacity of rated load of tires which is way over the actual vehicle weight for each tire needs to carry?

And how do you explain some tires state the following on the sidewall such as this tire used previously on my Honda CR-V:

YOKOHAMA AVID TRZ P205/70R15 95T
MAX. LOAD 680 kg [1499 lbs] AT 300 kpa [44 psi] MAX. PRESS.


Any person knows physics will tell your more air pressure will carry more weight / load, the upward curve can't be stopped at any air pressure going up until the tire blows up! :)


OK, let's try this one more time. I was part of a previous debate and don't recall anyone stating that 32 psi was where max load was rated (maybe it was a typo or a different debate). Nevertheless, Tirerack has this to say on this page: https://www.tirerack.com/tires/tiretech/techpage.jsp?techid=21

"It is important to note that the maximum load is rated at an industry specified tire inflation pressure that is often lower then the tire's absolute maximum tire pressure. The tire pressures used to determine the maximum load the tire is rated to carry is based on the sizing system industry standards applied to the tire."​

After a chart showing the various load pressures they go on to say:

"However, the tire's maximum inflation pressure may be greater, such as 300 kPa (44 psi) in this example or even 350 kPa (51 psi). This is done to accommodate the vehicle manufacturer's desire to tune the tires' high-speed capability, handling qualities and/or rolling resistance to better suit the vehicle."​

So why add air pressure for heavy loads, such as towing? It helps the tire maintain a better shape. With a heavier load the tire sidewall will tend to bulge or squat and additional pressure will help compensate for this, allowing your sidewall to flex a little less and not build up as much heat.

How do you explain many tires don't include the word AT or the symbol @?

I have 2 cars in my garage right now. The OE Toyo A23's on the CX-5 just say MAX LOAD 1709 LBS on one line and MAX PRESS 51 PSI on the line below but no AT or @ connecting them.
The General Altimax RT 43's on my wife's Nissan have the order reversed, MAX INFLATION PRESSURE 51PSI is on the top line and MAX LOAD 1201 LBS on the line below but no AT or @.

Finally, as a retired engineer, my physics knowledge is just fine, thanks. Above 35/36 psi the curve doesn't stop, it just doesn't count as far as load ratings go.
 
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