Stock tire PSI for the Speed 3?

[Andrade08]

I just put my OE wheels and tires back on yesterday because the snow of old man winter is over. I went to pump them with air and noticed that Mazda wants 34psi front and 32psi rear! The tires have a max PSI rating of 50psi. The #s look low? What do you guys run in your tires? I am **not** looking for max traction or ride comfort. I am looking for the tires to last as long as possible and the least rolling resistance on the freeway. My ride to work is 38 miles one way all freeway 70mph. I normally just run the max PSI on the tire on my cars. I have done that for 16 years with great results. But 50psi seems high and 34 psi seems low? I have the fronts at 44psi right now and the backs at 42psi and the fronts still seem too low but the rear looks to be inflated nice. The ride is still fine. OK that is my Q…….. :)

[ericrapp]

The pressure you should use is posted by the mazda folks on the inside of the door. The tire pressure max is just a reference to the tire only, not the car it is on. You might want to get a little closer to the 34 psi. The tire's traction changes alot with pressure. For a daily driver you can up it a couple pounds for gas mileage but be careful stopping in the rain. Just a suggestion 08. thinking about your safety is all.

[Andrade08]

Thanks for the reply. It is just that at 34 PSI the front tires look like they are going flat???

[sjeffrey]

Thanks for the reply. It is just that at 34 PSI the front tires look like they are going flat???

That's what you get with low profile. I'm not sure, but 50 PSI max tire rating, that's probably after the tire heat's up as well. I don't know how many PSIs a tire will gain after heat-up, maybe +/- 4 PSI??

I personally wouldn't go over 36/38 PSI

[SwampAss]

50psi would be for maximum pressure for the tire. GO by the specs on the door frame. That's manufacturer recommended. Tire pressures are ALWAYS measured cold. It would be 50psi cold.

[SPEED305]

no way! i ride on 32 on all four tires

[Silver Ecstasy]

My SS requires 32 psi all the way around. It suggests that if i'm going to be driving in excess of 90mph, to up the rear air pressure to 38 psi. I run 35 psi all the way around and have gotten the best possible gas mileage.

I'm assuming that's why they want the front wheels at a higher PSI (higher speeds). Not to mention, you have more weight in the front with the engine + trans. If the rears were at the same pressure, or higher, i'd also assume you'd risk throwing the rear end out in harder cornering. With lower pressure, the tirewalls will roll a little more to forgive any overcorrections.

[redspeed3tk]

at 44psi the center of your tread will be gone very quickly follow the recommended specs they are there for a reason

[Moonpie.Express]

I used 34 F and 32 R...always checked cold and rotated approx. every 3000 miles = over 25K on the stock tires.
And yes, I do force the traction a bit.

[Silver Ecstasy]

Maybe it's my opinion only, but I don't think it's that necessary to rotate every 3000 miles. That's a bit over the top don't you think? Maybe every 7,000 miles? Do you get your alignment done every 3k too? That makes a big difference on how the tires wear too.

[Moonpie.Express]

All I am saying is.....my practice netted 25K on these tires on the stock alignment. One was feathered towards the end and I chalk that up to alignment.

Rotating tires on this car is a snap. And you can do it with JUST your scissor jack.

[SwampAss]

I used 34 F and 32 R...always checked cold and rotated approx. every 3000 miles = over 25K on the stock tires.
And yes, I do force the traction a bit.

I sold my stock tires with 12k on them. They still had 6/32nds at the lower point. I could have easily gotten 25k out of them. I rotate every 5k during my oil change. My 235/40s look new after another 12k. Chewed to shit from the inside of my rear fenders.....but the tread is great!

[dirtyd]

All I am saying is.....my practice netted 25K on these tires on the stock alignment. One was feathered towards the end and I chalk that up to alignment.

Rotating tires on this car is a snap. And you can do it with JUST your scissor jack.


When rotating the stock tires, do the driver side tires stay on the driver's side of the car only? Or can you do a cross over i.e. Driver side front to passenger side rear? Wondering because of the tred...?

Thanks!

[Moonpie.Express]

YES, they stay on the same side!
The thing is, rotational direction must stay the same.

[SwampAss]

I don't think they are directional. I switched sides several times.

[Moonpie.Express]

I could be wrong, but I think they actually have directional indicators on them.
I thought most tires have this due to the way the belts wear.
If I wanted to switch sides, I would have to unmount and remount.

[SwampAss]

I looked and looked and saw nary an arrow.

[Moonpie.Express]

put your glasses on and look harder!



I have not looked yet...when I get to the house and have a beer in hand, I shall do a walk around.

I will also look at that damn Owner's manual that is taking up space in my glove box. It usually has more info than I need.

[MicaSp33d]

I say go with what the factory suggest.

I don't understand why people inflate their tires based on the max psi the tire can handle. Over pressuring tires will lead to premature wear and higher chances damaging tires when you hit a pot hole or a dip.

The factory gives you suggested specs based on thier testings ... i assume its based on the weight distrubution and size of the tires. Once your tire gets up to temp, your psi will raise around 4 or 5 psi.

the tire may look like its flat but look at it from the face of the tread, there is more of a contact patch which will give you better traction. You can up the psi a couple to get the steering more responsive and better mpg, but to me 44 psi is too excessive based on the recommended psi.

[BlackJack]

I usually give the front 36 and back 34 to give it better MPG and response. Hot days I would sometimes raise both by 2 PSI.

[ericrapp]

I sold my stock tires with 12k on them. They still had 6/32nds at the lower point. I could have easily gotten 25k out of them. I rotate every 5k during my oil change. My 235/40s look new after another 12k. Chewed to shit from the inside of my rear fenders.....but the tread is great!

ha Did you roll them or wait for the tires to conform to the fender? ha

[SwampAss]

I am still waiting to them to conform....or blow out. :)

[ericrapp]

I am still waiting to them to conform....or blow out. :)

I do respect your style

[ericrapp]

It seems most all high speed summer tires are directional, if you do your own tire rotations and the arrow on the sidewall is not apparent just look at the tread pattern it is easy to see. And silver ectasy i belieive you are on track about pressures. Just look at the front rear weight bias, very heavy front. I am amazed it doesn't understeer much more.

[Andrade08]

Our stock tires are **NOT** directional. You can put what ever rim/tire on what ever side you want. The mounting of the tire is what needs to be done right. There is an *inside* and *outside* marking on the tire but the tread pattern is not directional. Go look. The stock tire PSI from ALL car manufacturers is for good handling and comfort. Not for getting the most out of them wear wise and highway cruising. I have run the MAX PSI on my tires for 16 years and have never once wore out the center of any tire ever. I put over 60,000 miles on a set of tires that were on my 96 VW GTI. I ran them at 41psi front and 39psi rear. Tires had a max pressure of 44psi. They wore perfectly. On my Lightning I had over 30,000 miles on my stock tires before I took them off because I changed rims. They even wore perfect up front. Out back well…………..truck had a little over 500ft/lb torque so the tires were punished.
Running close to the max PSI on the tire is not going to wear the center of the tire. I have proven that to myself over years of doing it. Actually you get more miles out of a tire this way. Over inflating the tire past the max PSI will make it wear the center. Running more PSI will kill handling and give you a very HARD ride. But, you have much less rolling resistance on the freeway.
But, these tires become rocks at 45PSI and up so. As of now I have 39PSI front and 36PSI rear and it feals good all around. This is were I will stay.

[Silver Ecstasy]

I just can't fathom the max psi as safe.

If the tire's maximum pressure is 44 psi and you're running 40 psi, you're running real close to the limits of the actual tire. Atleast here in MI, one pothole and you'd wish you never had it at full psi. The most I think i'd run mine on the MS3 is 38 psi.

[MicaSp33d]

I just can't fathom the max psi as safe.

If the tire's maximum pressure is 44 psi and you're running 40 psi, you're running real close to the limits of the actual tire. Atleast here in MI, one pothole and you'd wish you never had it at full psi. The most I think i'd run mine on the MS3 is 38 psi.


I agree ...


"max psi" is a precaution and not a suggestion.

[Silver Ecstasy]

Exactly. That's why I think Mazda is so smart. They know that most people buying the MS3 are going to redline the engine consistently being it's a turbo'd 4cyl. So to prevent damage, they restrict power 500 rpms before redline begins.

Somewhat similar analogy.

Either way though, yeah I've ruined a set of Yokohama AVS-E100 because they weren't properly inflated for atleast 8,000 miles. I was young and didn't know any better, and they came out wavy as hell. I learned my lesson and check my tire pressure constantly.

[Bravnik]

Read every post and still have no idea what the best PSI should be....You guys Fail!!!! :)

[fasteract]

Rule of thumb on the motorcycle racetrack was to set a cold pressure which than showed an increase of 10% when hot...for ex., 36 cold...39.6 when hot. If hot psi is too low, make the tire softer cold and viceversa.

[dgraf]

Andrade youre being a dumbass. Why the hell did you start this thread if you aren't going to listen? You seem very ignorant. You get a performance car and try to get longetivity out of the tires? Something doesn't make sense to me here. CHEERS!

[ericrapp]

Read every post and still have no idea what the best PSI should be....You guys Fail!!!! :)

Dude Its on the door. If when you open the door and look directly aww f IT is 34 32 and you can vary that a couple pounds for personal preference. More pressure =a bit stiffer ride. Less pressure= softer over bumps, but more sidewall flex when turning imo. peace