Welcome to the North American Subaru Impreza Owners Club Friday March 29, 2024
Home Forums Images WikiNASIOC Products Store Modifications Upgrade Garage
Click here to visit TireRack
Tire & Wheel Forum sponsored by The Tire Rack

Losing traction? Need new tires?
Click here to visit the NASIOC Upgrade Garage...
Go Back   NASIOC > NASIOC Technical > Tire & Wheel

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.







* As an Amazon Associate I earn from qualifying purchases. 
* Registered users of the site do not see these ads. 
Reply
 
Thread Tools Display Modes
Old 11-07-2020, 06:12 PM   #1
fullah
Scooby Newbie
 
Member#: 233053
Join Date: Dec 2009
Default Dunlop sport maxx rt uneven thread depth normal?

Can someone tell me if this is normal because all four tires have the same measurements. From the inside edge and middle of the tire it's showing between 7/32 to 8/32. Specifically these were bought used from a 2015 sti in 245/40/18.

Not sure why the seller sold them but I bought all four for $175 which at the time seemed too good to be true but I bought them. Chasing down a low speed wobble/vibration/highway swaying but trying to rule out if it's tire related or drivetrain related.



However toward the outside of the tire the measurement goes to between 4/32 to 5/32. I'm taking the measurement at the area circled. Is this normal?

* Registered users of the site do not see these ads.
fullah is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 11-07-2020, 11:21 PM   #2
krzyss
Scooby Specialist
 
Member#: 8365
Join Date: Jul 2001
Location: Massachusetts
Vehicle:
2019 Mazda MX-5 RF
Machine Grey

Default

I think you now know why the seller was selling the tires.
Tread depth should be uniform, AFAIK.

Krzys
krzyss is offline   Reply With Quote
Old 11-08-2020, 08:15 AM   #3
fullah
Scooby Newbie
 
Member#: 233053
Join Date: Dec 2009
Default

Yea it makes sense now why they were so cheap. My understanding has always been that the depth should be the same across the tire but since all 4 were like this I was doubting myself thinking thats just how the tires are designed.

I used to live in a state where the speed limit is 55. Now I live in a state where the speed limit is 65 and everyone is doing 80. So definitely driving the car at 75 mph feels like its falling apart. Where as I didnt notice it as much going 50-55 mph.

Within the last few weeks the car has also been aligned. Everything is in green besides the rear camber because im lowered on factory lower control arms. I even had all four tires road force balanced which didnt change anything.

I also noticed my braking feel like it's faded especially in the rain and the vibrations get even worse on wet pavement. Already verified engine mounts and trans mount aren't moving. It was basically coming down to the tires or maybe driveshaft, axle or transmission issue at this point but since the car behaves differently depending on the rain my suspicion was with the tires..

So what causes this kind of outside edge wear? I don't really see any signs it was an alignment issue (it this from too much positive camber?). Is this from previous owners driving a certain way?


Last edited by fullah; 11-08-2020 at 08:21 AM.
fullah is offline   Reply With Quote
Old 11-09-2020, 09:57 AM   #4
Norm Peterson
Scooby Specialist
 
Member#: 498642
Join Date: Mar 2019
Chapter/Region: Tri-State
Location: our wrx IS the family sedan
Vehicle:
'19 WRX Ltd 6M dgm
'08 Mustang GT (the toy)

Default

Is that picture showing the alignment before or after anything was adjusted?

Typically, hard cornering combined with camber that's not far enough negative will beat up the outer portion of the tread. Especially with a strut front suspension. And more so if the tire was also underinflated. If all four were about the same, it at least looks like the guy rotated the tires around on his car.

At least check the tread depths in all of the fully circumferential grooves for a more complete picture of tread wear. FWIW, it's not impossible for those little hockey-stick shaped grooves to be intentionally a couple of 32nds shallower than the main grooves.


Norm
Norm Peterson is offline   Reply With Quote
Old 11-09-2020, 02:23 PM   #5
fullah
Scooby Newbie
 
Member#: 233053
Join Date: Dec 2009
Default

Those alignment specs are after the adjustment. The rear camber is off because it's lowered on stock control arms. The 4/32 to 5/32 measurement in the orange circled area is measuring the groove that goes north to south. I'm guessing based on what I've read so far that grooves measurement should also be around 8/32 as the rest of the tire
fullah is offline   Reply With Quote
Old 11-09-2020, 02:40 PM   #6
Norm Peterson
Scooby Specialist
 
Member#: 498642
Join Date: Mar 2019
Chapter/Region: Tri-State
Location: our wrx IS the family sedan
Vehicle:
'19 WRX Ltd 6M dgm
'08 Mustang GT (the toy)

Default

Quote:
Originally Posted by fullah View Post
Those alignment specs are after the adjustment.
Thanks. Better that you tell me than me hoping that I did guess right.


Quote:
The rear camber is off because it's lowered on stock control arms.
Understood. Lowering will do that to most cars with independent suspensions (at either end) unless/until you adjust it out.


Quote:
The 4/32 to 5/32 measurement in the orange circled area is measuring the groove that goes north to south. I'm guessing based on what I've read so far that grooves measurement should also be around 8/32 as the rest of the tire
I don't think I'd make that assumption, especially where it's a summer performance tire being discussed. Shallower tread grooves near the outboard shoulder make the tread blocks stiffer, and the handling is sharper and more precise as a result.

In a straight line (which certainly describes where most peoples' hard braking on a wet street happens), the outside shoulder area isn't where a disproportionately high amount of braking happens. Negative camber shifts the hard work more toward the inboard shoulder, and nose dive under braking pushes the actual operating camber of the front tires even further negative than what you get on your alignment rack printout.


Norm
Norm Peterson is offline   Reply With Quote
Old 11-09-2020, 05:58 PM   #7
fullah
Scooby Newbie
 
Member#: 233053
Join Date: Dec 2009
Default

Thank you for the technical explanation. So this puts me back at square one wondering if this is how the tires should be. I was hoping someone with these tires could confirm. I have a new set of tires on order but it's wishful thinking that it will fix my issue. I am not sure the tires are the issue since I don't know what they're supposed to measure.

Not sure why my iPhone is adding these extra characters in my post. Will edit on my computer.
fullah is offline   Reply With Quote
Old 11-11-2020, 09:22 AM   #8
Norm Peterson
Scooby Specialist
 
Member#: 498642
Join Date: Mar 2019
Chapter/Region: Tri-State
Location: our wrx IS the family sedan
Vehicle:
'19 WRX Ltd 6M dgm
'08 Mustang GT (the toy)

Default

I rather doubt that Dunlop would be willing to share that data, so I think you'd have to measure the groove depths in a brand new tire, at several places around the circumference. I suppose one could take an actual tire tread depth gauge or similar measuring device and take a few quick measurements of the tires on a new and unsold WRX sitting out on the dealership lot.


Best guess I have for the "'" strings is that something in your phone isn't understanding the special apostrophe character.


Norm
Norm Peterson is offline   Reply With Quote
Old 11-11-2020, 07:03 PM   #9
fullah
Scooby Newbie
 
Member#: 233053
Join Date: Dec 2009
Default

So I had a chance to get the car on four jackstands so get the wheels spinning. So the tread depth issue is probably the least of my worries as you can see in the videos below. The driver front tire has a hop to it. The driver rear the wheel/tire combo is wobbling. The "best" two wheel tire combo were the passenger front and passenger rear.


I rotated the passenger rear to thedriver front and the wandering has dimished significantly plus the steering wheel shimmy has diminished as well. Now since both messed up wheels are in the back I definitely feel it more in the floor board/lower down in the car which is expected. Hard to tell if these are issues with the tires or the wheels or both. In one of my other threads I posted that I felt like the traction control was coming on and the car was hestiating. I thought it was the steering angle sensor. I'm thinking it was because of the hopping tire and the car trying to correct.

I'm kinda upset the tire shop didn't pick up these issues especially when they used a road forced machine. I know for a fact I didn't hit any pot holes after I got them road forced balanced so this was an existing condition.

Also I think my front sway bar links are worn. I don't think I should be able to move them by hand this easily. Could be the shimmy has put extra stress on them but still weird for only having 9,200 miles.

Videos:https://photos.app.goo.gl/XEzd1Ww4wRTeT7uE6

Have new tires coming just need to pick a set of wheels.
fullah is offline   Reply With Quote
Old 11-16-2020, 08:20 AM   #10
Norm Peterson
Scooby Specialist
 
Member#: 498642
Join Date: Mar 2019
Chapter/Region: Tri-State
Location: our wrx IS the family sedan
Vehicle:
'19 WRX Ltd 6M dgm
'08 Mustang GT (the toy)

Default

Quote:
Originally Posted by fullah View Post
Also I think my front sway bar links are worn. I don't think I should be able to move them by hand this easily. Could be the shimmy has put extra stress on them but still weird for only having 9,200 miles.
It's OK for endlinks to swivel on their spherical joints freely like that as long as there is no detectable lateral or axial play. It's probably better if they do than if they stiffly resisted rotation, as free rotation means there's less "stiction" in the suspension.


Norm
Norm Peterson is offline   Reply With Quote
Old 11-16-2020, 09:08 AM   #11
krzyss
Scooby Specialist
 
Member#: 8365
Join Date: Jul 2001
Location: Massachusetts
Vehicle:
2019 Mazda MX-5 RF
Machine Grey

Default

"Stiction" - that sounds very scientific!

;-)

Krzy***347;
krzyss is offline   Reply With Quote
Old 11-16-2020, 09:37 AM   #12
Norm Peterson
Scooby Specialist
 
Member#: 498642
Join Date: Mar 2019
Chapter/Region: Tri-State
Location: our wrx IS the family sedan
Vehicle:
'19 WRX Ltd 6M dgm
'08 Mustang GT (the toy)

Default

Quote:
Originally Posted by krzyss View Post
"Stiction" - that sounds very scientific!

;-)

Krzy***347;
It actually is a real term.


Norm
Norm Peterson is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

All times are GMT -4. The time now is 01:14 AM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2024 Axivo Inc.
Copyright ©1999 - 2019, North American Subaru Impreza Owners Club, Inc.

As an Amazon Associate I earn from qualifying purchases.

When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission
Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.