Tire PSI preference?

[Deleted member 69311]

For the past year (almost 2) I’ve driven on 28-29psi. During the summer it was at 31psi.

Right now during the rainy and cold season in WA, I have it set at 27psi (warning light comes on at 25psi.) I have it set that low so I can get more grip, especially in the rain. I feel like the car would kick out more when throttling if my psi is higher.

Is low psi (27psi) going to cause any sort of premature wear other than the normal wear and tear of driving? Should I bring it up to 30, or the standard 32?

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[Pistol_91]

What does the tire say it should have? Are they normal street tires? If yes then lowering the psi isn't going to give it more grip if it's not a drag radial or slick. The tire is designed and tested to run at a certain psi for a reason. I used to chuckle watching kids lower their street tires psi at the track to like 15 psi to do absolutely nothing.

 

[Skye]

I've attached links to two tools I use: 1) and air pressure gauge and 2) tread depth gauge.

Tire pressure will impacted by the volume and type of the tire, so the optimum pressure might be a bit different for all of us. What brand of tire, type, size and traction rating does the current tire have?

I'm using aftermarket tires (285/35/19) and rims (19x10), which are quite close to the volume of the originals. I ultimately settled on 33 psi / 2.27 bar. I check the air pressure manually at least every two weeks, or after a large change in temperature. I maintain the same psi, regardless of temp.*

Tread depth is checked and documented (I draw a picture and put in the log book) every few hundred miles. I learned over time I got the most consistent (flat) tread pattern using the pressure above. YMMV.

Checking pressures and treads as often as I do could seem a bit much. I don't mind. Along with pressures and their impact, mapping the tread depth will help determine how well (or not) your alignment and suspension is, before you realize one or more tires (or part) need to be replaced. "I was washing my car today and I cannot believe what this tire looks like!" More importantly, for those spirited runs, I have confidence the treads and pressures are good.

The effect of the rear kicking out on acceleration, that could be caused by the tire pressure, but could also be caused by alignment, suspension, tire compound, even the drive mode (if equipped) you're in.

How close is the current operating pressure to that of the manufacture's recommended pressure? How does the car act when operating at the recommended pressure?

When is the last time the alignment was checked? Do the tires appear to be wearing normally now?

I think anyone who has done so has given very positive feedback to securing the rear, with IRS brace kits and/or stiffer bushings.

I've learned Track mode is more tactile, more linear on the throttle while Sport+ and other modes are not (IMO).

I don't do any heavy acceleration or spirited driving when wet. I have A/S tire, but wet conditions complicate things. If it has rained a little, the surface will be slicker than if rained more. Especially in a new area, it can be difficult to determine how deep a divot is. I do understand living where you do driving in the wet is probably more common than driving in the dry.

https://www.autometer.com/performance-analog-tire-pressure-gauge.html

I've enjoyed the Autometer guage. Between the TPMS, my old pen-style manual gauge and the Autometer, I learned my pen-style gauge was not accurate. From my experience, the factory TPMS rounds up/down; the display rounds up one psi if the pressure has increased by .5+ and rounds down one if the psi has changed -.5 or greater.

https://miltonindustries.com/products/miltonr-tire-tread-depth-gauge-single-retail-pack-s-448w

*If the car is in storage, tire pressures are temporarily increased to 40 psi / 2.75 bar.

 

[Geodudes550]

I’ve got a staggered setup on 20’s so I’ve got 30 in the front and 32 in the back.

 

[njweatherman]

My 2020 GT premium door sticker had all 4 set at 33 PSI. My 2023 door sticker lowered all 4 to 32 PSI. During the winter here in NJ, I keep mine around 33 - 34 when cold. So, when I drive, it goes up to 35 to 36. Summer time, I pretty much do the same. I don't really notice anything. BTW - I have the stock all season Pirelli's on.

 

[GrabberBargeCaptain]

Most of my other cars I would increase the tire pressure by a few PSI for a bit crisper steering and slightly better mpg... I upped the Mustang from 32 to 36 and traction was pretty negatively affected at full throttle especially in colder temps. You know, when the stability control kicks in and the car starts swaying side to side while you're gunning it in first gear in the upper RPMs? Very unsettling feeling. I now keep it around 32.

 

[jlchoutex]

Should use what the vehicle recommends.

 

[K Myers]

For the past year (almost 2) I’ve driven on 28-29psi. During the summer it was at 31psi.

Right now during the rainy and cold season in WA, I have it set at 27psi (warning light comes on at 25psi.) I have it set that low so I can get more grip, especially in the rain. I feel like the car would kick out more when throttling if my psi is higher.

Is low psi (27psi) going to cause any sort of premature wear other than the normal wear and tear of driving? Should I bring it up to 30, or the standard 32?

What do you prefer traction or tire wear it's all about choses I run my nittos g2 's @ 26-27 year round I'm in FLA

 

[NightmareMoon]

Look, its going to depend on the tire. what tire and size are you running?

yes running a tire too low and it will wont wear as evenly across the tread (which means you’ll have to toss it a little early), and with less pressure the sidewalls wont be supported as well so some handling might be affected (it can get sloppy), but not all tires are created equal.

Generally, 32 is a good number to start with, it should be in the happy zone for many tires on a mustang (which is why its the factory recommendation for a lot of our cars)

 

[K4fxd]

The good years wanted 35 psi and the Pirelies want 28 on my car. Best traction even tire temps.

The door sticker is a recommended pressure, the tire sidewall is a max pressure.

 

[PoCoBob]

I knew when I bought the car it was going to be a bit harsh with the 20" rims and a low profile sidewall. Door sticker says 35 psi and that pressure means no give to the sidewall at all and in the summer they inflate to 40-41 psi from driving. Now I set them at 32 psi cold and they rarely inflate to more than 36 psi when driving and that has made a noticeable improvement. I wouldn't be comfortable trying anything lower than 32 with such a low sidewall.

 

[Schuvwj]

I have 275/35-20” on all corners. Roush recomends nothing less than 35psi cold.
I found that 38psi in the front and 35psi in the rear brings the best overall results for traction, grip and tire wear.

 

[Hoofer]

Should use what the vehicle recommends.

^This.

 

[Torched10]

Under inflating will cause more wear on the outsides of the tires.i keep mine at 32psi cold. 35 gives more bounce in steering wheel as psi goes up as you drive it esp in summer

 

[Deleted member 69311]

Look, its going to depend on the tire. what tire and size are you running?

yes running a tire too low and it will wont wear as evenly across the tread (which means you’ll have to toss it a little early), and with less pressure the sidewalls wont be supported as well so some handling might be affected (it can get sloppy), but not all tires are created equal.

Generally, 32 is a good number to start with, it should be in the happy zone for many tires on a mustang (which is why its the factory recommendation for a lot of our cars)

I have CONTINENTAL EXTREME CONTACT DWS06 PLUS.
I think I’ll inflate them to 32psi while it’s still cold out.

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