Mazda5 Toyo Proxes 17in OEM tires, What is the ideal psi?

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coolmazda5

Member

Contributor

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2008 Mazda5 5MT Sport w/ Popular Package

• Feb 28, 2008

• #1

Yes, yes, I know the OEM tires kind of suck but I cannot spend money on buying new ones until these ones wear out.

In the meanwhile, now that I have a Mazda5 as the daily driver I noted that during cold days the tires make the road feel rougher (like overinflated) and there is actually some minor vibration when accelerating on 3rd, 4th and 5th gears. Once they warm-up all that is gone, except if its extremely cold (not Canadian cold, but let's say 20F or less)

I keep them at 34psi (cold), so the question is: What psi is ideal? Only one of my old cars had low profile tires, so I'm noob on this

Thanks!

 

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mde8965

Member

• Feb 28, 2008

• #2

Other than the OEM's version of ideal (aka the pressures given on the sticker in the door jamb) I don't think there is an ideal pressure. It is different for each person based on the condition of the roads they travel, climate and load they normally carry.

For instance, I keep mine at 35-36lbs. That's a bit above the OEM recommendation, but I do so to hopefully make them last a little longer. I generally am not fully loaded and the conditions of the roads here in Florida is very good/smooth and the extremes in temp are to the hot side, not the cold side.

Obviously, you are looking for that right balance between comfortable ride (at lower pressures) and maximum tire life (at higher pressures). With the low profiles you want to be very careful not to run on low pressure on bad roads or else run the risk of damaging a wheel. You being in a colder climate, I am surprised that they ride rougher when cold unless they are underinflated... which I wouldn't think they would be at 34psi. You could try adding a lb or 2 to see if it helps...and if not or it gets worse, go back and try going a bit lower than 34.

 

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diogenes

Member

• Feb 28, 2008

• #3

I keep mine 2 lbs over the recommended all the way around, and have found this to improve MPG a smidge without affecting ride noticeably, but it never really gets much below freezing here (Portland, Ore.)

I think below-freezing temps may degrade ride by making the oil in the struts thick even more than by affecting the tires.

 

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mrbwa1

Member

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2007 Mazda5, 2001 Toyota ECHO

• Feb 28, 2008

• #4

Way to bring up one of those hotly disputed topics int eh car world! Technically, they should run at the stated 34PSI. I have always run higher for a little better MPG at the expense of Ride quality. I run the Toyo Summer tires at 38PSI and the 16" snows at 40PSI. Seems to be the best balance so far. Honesty, the factor rims were only on for a month, so I might have to dial it in when summer comes.

The big deal with 50 series tires is to keep up on the Air pressures. The low profile sidewalls are so thin that they don't really bulge when underinflated like the old 70 and 80 series tires.

 

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Evan_in_CA

Member

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2006 Mazda5 Touring

• Feb 28, 2008

• #5

I run all the tires on all my cars at the max printed on the sidewall. It does make the ride a bit more harsh, but maximizes fuel economy and the tires wear perfect. This is primarily based on my experience with my VW Jetta, which I've put 175k on in the past 4 years.

IMHO, the manufacturer's recomendations are obscenely low, designed to give a cushy ride, not to maximize the life of the tires.

 

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mrbwa1

Member

:

2007 Mazda5, 2001 Toyota ECHO

• Feb 28, 2008

• #6

Evan_in_CA said:

I run all the tires on all my cars at the max printed on the sidewall. It does make the ride a bit more harsh, but maximizes fuel economy and the tires wear perfect.

Click to expand...

I used to follow that philosophy, but my newer cars have the low profile tires and max pressures in the 45+ PSI range. The Snows on the 5 have a max pressure of 51 PSI!

 

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07MZ5SA

Member

:

2007 Mazda 5

• Feb 28, 2008

• #7

A set of factory seat covers should absorb some road vibration to your hips (works for me).

 

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Evan_in_CA

Member

:

2006 Mazda5 Touring

• Feb 28, 2008

• #8

mrbwa1 said:

I used to follow that philosophy, but my newer cars have the low profile tires and max pressures in the 45+ PSI range. The Snows on the 5 have a max pressure of 51 PSI!

Click to expand...

Yup, the tires on my Jetta have a max of 51 and that's what I keep em at. The tires that are on the rear right now have 108k miles on them, they are just past the wear bars and worn perfectly even all the way across. They spent their first 65k on the front of the car.

 

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jeebusm3

Member

:

yes

• Feb 29, 2008

• #9

Evan_in_CA said:

I run all the tires on all my cars at the max printed on the sidewall. It does make the ride a bit more harsh, but maximizes fuel economy and the tires wear perfect. This is primarily based on my experience with my VW Jetta, which I've put 175k on in the past 4 years.

IMHO, the manufacturer's recomendations are obscenely low, designed to give a cushy ride, not to maximize the life of the tires.

Click to expand...

wow. A lot of tires running too much PSI will wear in the middle. Not to mention in hot climates (like Los Banos in the summer), the PSI can get dangerously high. I'm guessing you have it down pretty well though, if you've managed such high mileage.

 

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rweatherford

Member

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Mazda 5

• Feb 29, 2008

• #10

I'm on 45 PSI and noticed the "vibration" from flat spotting while sitting has pretty much gone away.

 

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miwhite

Member

:

Mazda5

• Feb 29, 2008

• #11

All season tires are made with rubber compound that begins to harden at 7C. 20F is a lot less than 0C (32F), so your tires will have substantially hardened by 20F. Winter tires are made with rubber compounds and sipes that allow the tire to remain supple down to around -30C.

 

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Evan_in_CA

Member

:

2006 Mazda5 Touring

• Feb 29, 2008

• #12

jeebusm3 said:

wow. A lot of tires running too much PSI will wear in the middle. Not to mention in hot climates (like Los Banos in the summer), the PSI can get dangerously high. I'm guessing you have it down pretty well though, if you've managed such high mileage.

Click to expand...

Well, manufacturers want you to measure cold pressure, before the tires are run on, so if I set the tires to max pressure when it's 110 degrees out then there really is no problem, I'm setting the pressure before the tires are used. In a perfect world, if you were to set the pressure at the max in the dead of winter then the tires will be severly overinflated by summer, but it's not a perfect world and all tires will leak a little air over time. So even if you were to fill the tires on the coldest day in january, by the time the hot weather comes odds are your tires are going to be pretty underinflated, even if you have never checked the pressures since january. I suppose that if you set them at the max in a cold locale, then drove in the same day to a very warm place, then you would have overinflated tires when you arrive. I actually did a trip like that last summer and had to bleed some air off of the tires on a travel trailer at every rest stop.

YMMV, of course...(flash)

 

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coolmazda5

Member

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2008 Mazda5 5MT Sport w/ Popular Package

• Feb 29, 2008

• #13

Well, thanks all for the replies. I did not open a can of warms but I was close I would say

I have added 2 PSIs to each tire (~36 cold) and I have felt a little bit of a stiffer ride (obvious) but somehow a "less" pronounced vibration when cold. For the next service I'll ask them to check the balance, although I know (with my 06) than these tires are not the best, period.

I never cared about tire pressure frequent checks when I owned a Chevy Cavalier or a Honda Civic so the low profile tires "care" is a little bit obnoxious, yet the way they make the car look and drive once warmed-up is worth every road bump.