Tire psi Q?

[gabriel9766]

So my factory continental procontacts have 19k on them, i run what the door says 35psi but my tires are wearing like they are under inflated.
All tires are wearing 7,8,8,7/32's on all 4 tires. Should i inflate them a lil more?

 

[old1]

I would, but that is just me, as I always run 2 0r 3 lbs over sticker.

 

[ET16]

Originally Posted By: old1
I would, but that is just me, as I always run 2 0r 3 lbs over sticker.


I usually do, too.

 

[OVERKILL]

What are you using for a tire pressure gauge? Have you verified its accuracy?

 

[CapriRacer]

Originally Posted By: gabriel9766
So my factory continental procontacts have 19k on them, i run what the door says 35psi but my tires are wearing like they are under inflated.
All tires are wearing 7,8,8,7/32's on all 4 tires. Should i inflate them a lil more?


It might be helpful if you told us what vehicle is being discussed. That could have a large bearing on what might be going on. The problem could be in the vehicle and it could be where you are driving.

 

[gabriel9766]

Originally Posted By: CapriRacer
Originally Posted By: gabriel9766
So my factory continental procontacts have 19k on them, i run what the door says 35psi but my tires are wearing like they are under inflated.
All tires are wearing 7,8,8,7/32's on all 4 tires. Should i inflate them a lil more?


It might be helpful if you told us what vehicle is being discussed. That could have a large bearing on what might be going on. The problem could be in the vehicle and it could be where you are driving.
the car in my signature, 2015 chevy malibu with 215/60/16 as the tire size.

 

[benjamming]

Originally Posted By: OVERKILL
What are you using for a tire pressure gauge? Have you verified its accuracy?


This.

 

[bioburner]

I've had more than one POS gauge.

 

[gathermewool]

Originally Posted By: bioburner
I've had more than one POS gauge.


I've got to toss another one. In my case, it reads 5#+ low. I inflated to 34 and it was closer to 40 on my others. Well, either that or one is good and my other two read the same at 5# low...

What's the inside, outside, middle tread depth?

 

[UltrafanUK]

Running the tyres a few PSI higher than book or door placard does help if the wear is on both edges, as does rotating the tyres. If the shocks or struts are old the tyres will wear slightly more on the outsides.
Obviously make sure the tyres are not wearing in spots, as that is caused by poor tyre balance.

7,8,8,7 is probably normal for a car tyre that is used on bendy roads.

 

[gabriel9766]

Originally Posted By: gathermewool
Originally Posted By: bioburner
I've had more than one POS gauge.


I've got to toss another one. In my case, it reads 5#+ low. I inflated to 34 and it was closer to 40 on my others. Well, either that or one is good and my other two read the same at 5# low...

What's the inside, outside, middle tread depth?
i use my digital mac tools Guage to check tire pressure.

 

[CapriRacer]

Originally Posted By: gabriel9766
the car in my signature, 2015 chevy malibu with 215/60/16 as the tire size.


Oops! Sorry! [Note to self: Look in the signature next time!!]

OK, 2 possibilities occur to me:

1) It's an old tire engineer's trick to use less tread depth in the shoulder ribs to improve rolling resistance. Maybe this tire started off 1/32nd smaller and has stayed that way - so in some respects, it is wearing evenly, it just didn't start off even.

2) Steer tires tend to wear in the shoulders. I wonder if what you are seeing is an artifact of that - and over time it will continue to get worse.

Suggestion: I don't see any harm to boosting the inflation pressure by 3 to 5 psi. Then very precisely measure the tread depths - to the nearest tenth of a mm if you can. You'll have to do it in at least 3 spots - and I would suggest 6 evenly spaced places if you can. Then in 10,000 miles, do the measurements again. See if that is having the effect you want.

Just an FYI: Radial tires aren't as wear sensitive to inflation pressure as the old bias ply tires used to be. There are lots of things that have a greater effect - such as alignment.

 

[Eddie]

The values given don't demonstrate under inflation. Check the wear across the tread from inner to outer to determine if over or under inflation. Ed

 

[Falken]

I am running 185/65R/15 Conti Truecontacts on my Fit and it doesn't handle well unless I fill them to 40PSI even.

Not sure if it is the result of not running stock tire widths or not.

It is a completely different car at a higher tire pressure, so that is where I keep it.

 

[Donald]

I like to use the new air machines that add and subtract air to get it right. Even though I have a couple of air compressors at home.

OP - verify your gauge.

 

[Smoky14]

Originally Posted By: Donald
I like to use the new air machines that add and subtract air to get it right. Even though I have a couple of air compressors at home.

OP - verify your gauge.

Discount tire uses these machines and I find them to be very inaccurate, as much as 3PSI from tire to tire.
YMMV

Smoky

 

[gfh77665]

Originally Posted By: gabriel9766
I run what the door says 35psi but my tires are wearing like they are under inflated.
....Should i inflate them a lil more?


They might be underinflated. Are you measuring PSI when the tires are cold, like after sitting still overnight? All too often people stick a gauge on a tire thats just been driven on. They naturally warm up and it will read 3-5 PSI too much. It later cools off and then you have 30 or even less.

Measure when cold, and pump them up!

 

[old1]

On the same vein, what is the best (and simplest) way to determine the accuracy of a tire pressure gauge? I usually have have 3 gauges, and compare them against each other, and if one is off by more than 2 lbs from the rest, I figure it is bad and chuck it. Is that the best a person can do? I read somewhere once that the digital gauges are the most accurate. Is that true? If so I would think having one of those to compare the others to would be the thing to do.

 

[CapriRacer]

Originally Posted By: old1
On the same vein, what is the best (and simplest) way to determine the accuracy of a tire pressure gauge? I usually have have 3 gauges, and compare them against each other, and if one is off by more than 2 lbs from the rest, I figure it is bad and chuck it. Is that the best a person can do? I read somewhere once that the digital gauges are the most accurate. Is that true? If so I would think having one of those to compare the others to would be the thing to do.


I think the *Odd Man Out* theory is as good as your are going to get.

My short term experience with digital gauges is that they are indeed accurate - but I don't have any long term experience, and that was about 10 years ago. Things may have changed.

Just an FYI: In the lab, we had a test fixture to verify the accuracy of our pressure gauges. According to the ISO procedure we needed to do that quarterly.