Questions on my Alignment

ManBearPig

Well-Known Member
Joined
Sep 14, 2015
Posts
1,128
Reaction score
271
Location
Nashville
Vehicle(s)
2016 GT
I have a 2016 GTPP with right at 9k miles. Up until now it has been just a weekend car, but its now going to become my daily driver.

When the car had about 2,500 miles, I put on a set of very mild 1" drop springs (Steeda Sport Linear). I had an alignment done about 500 miles later.

I aligned it to the FRPP recommended specs, or at least as close as I could get.

The initial reading was -1.9* camber on the driver front, -1.4* on the passenger front. This was adjusted to -1.6* on the driver side, -1.5* on the passenger side. Toe was set to 0.0

The rear camber was -1.9* on both sides with .1 toe on each side (.2 total toe) which is exactly what the FRPP spec calls for so we did not touch this.

I have a few questions. At 9k miles the rear PZero's are, quite tiny frankly, worn the F out. They are 110% bald on the outside, and have just a touch of tread left on the inside. Isn't this backwards of what such an aggressive rear camber would normally show? I had planned on getting the rear camber adjusted down to something more suited for daily driving (1.3* or so) but seeing this tire wear makes me rethink this. The front tires are not noticeably worn at all, and they seem to be wearing very evenly.

Something else worth noting...I've been running a 25mm wheel spacer on all 4 corners. The alignment was done with these in place. I've considered removing them now that I'll be daily driving the car (don't want road debris thrown down the side of the car). In theory, having a more aggressive wheel offset will exaggerate the negative camber, right? Will removing the spacers effectively bring the alignment back closer to an ideal daily spec? Maybe a few tenths or so? Or is this completely unrelated?




So, cliff notes....Why are the insides of my rear tires actually wearing *less* than the outside with close to 2 degrees of negative camber? And do wheels spacers have any noticeable effect on alignment?

Thanks
 

BmacIL

Enginerd
Joined
Sep 21, 2014
Posts
15,029
Reaction score
8,831
Location
Naperville, IL
Vehicle(s)
2015 Guard GT Base, M/T
Vehicle Showcase
1
This is normal for Pzeros. They wear terribly. 10k miles is about the average for bald rears. You could bring the rear camber down some, but overall the alignment is good.
 
OP
ManBearPig

ManBearPig

Well-Known Member
Joined
Sep 14, 2015
Posts
1,128
Reaction score
271
Location
Nashville
Vehicle(s)
2016 GT
  • Thread starter
  • Thread Starter
  • #3
This is normal for Pzeros. They wear terribly. 10k miles is about the average for bald rears. You could bring the rear camber down some, but overall the alignment is good.
I'm not at all concerned that the tires are shot, just find it odd that they are worn more on the outside than the inside with a somewhat aggressive negative camber. I would expect it to be the other way around, right? Also wondering how much impact the wheel spacers have on alignment, if any.
 

BmacIL

Enginerd
Joined
Sep 21, 2014
Posts
15,029
Reaction score
8,831
Location
Naperville, IL
Vehicle(s)
2015 Guard GT Base, M/T
Vehicle Showcase
1
I'm not at all concerned that the tires are shot, just find it odd that they are worn more on the outside than the inside with a somewhat aggressive negative camber. I would expect it to be the other way around, right? Also wondering how much impact the wheel spacers have on alignment, if any.
None. They don't change the camber or toe. Pzeros also have a history of wearing funny. What are your pressures? I don't think you'll see an issue on a different (better) set of tires.
 

NightmareMoon

Well-Known Member
Joined
Nov 22, 2015
Posts
3,034
Reaction score
1,630
Location
Austin
Vehicle(s)
2016 Mustang GT PP
Vehicle Showcase
1
Good idea to check pressures. If his tire pressure is too low it might wear more on the edges and less in the center, but ya that's a little odd to be out of tread on the outside if you aren't using those tires for autocross or track days. Spacers shouldn't affect it.
 
OP
ManBearPig

ManBearPig

Well-Known Member
Joined
Sep 14, 2015
Posts
1,128
Reaction score
271
Location
Nashville
Vehicle(s)
2016 GT
  • Thread starter
  • Thread Starter
  • #6
Ive been running 32 psi at all 4 corners. No track days, just some spirited driving around town. Wear seems even across the tire with the exception of the inner tread block. Its so minor that I guess I'll just put a new set of tires on and monitor it. I can't see the need to decrease the negative camber, though....as I haven't experienced any negative tire wear that I believe to be related.

Ive read some conflicting info about wheel offset and alignment. It does make sense that the further away from the hub a measurement is taken, the more exaggerated that measurement may be just due to the way a lever works. I'm not the best with geometry but it would seem that pushing the measurement an inch further away from the hub would tend to inflate any readings. Is this effect just not enough to be considered?
 

NightmareMoon

Well-Known Member
Joined
Nov 22, 2015
Posts
3,034
Reaction score
1,630
Location
Austin
Vehicle(s)
2016 Mustang GT PP
Vehicle Showcase
1
The lever action comes into play for a few things, but not for camber or toe measurements.
 
OP
ManBearPig

ManBearPig

Well-Known Member
Joined
Sep 14, 2015
Posts
1,128
Reaction score
271
Location
Nashville
Vehicle(s)
2016 GT
  • Thread starter
  • Thread Starter
  • #8
Revisiting this as I am about to get the car aligned again. I know I need less negative camber all around but not sure how much less. I'm going to order some camber bolts for the front (not as good as caster camber plates I know but eaaaay cheaper) and the rear should have plenty of adjustment.

For a street car that sees some commuting and weekend backroad driving what should I shoot for? Can I try to get to -1ish all around? Should I try to keep more negative camber on the front than the rear?

Maybe close to -1.3 front and close to -1.0 rear?
 

Roadway 5.0

Strassejager
Joined
Dec 19, 2016
Posts
1,118
Reaction score
1,242
Location
New York - USA
First Name
Mike
Vehicle(s)
2016GT PP 6MT
Vehicle Showcase
1
If your ultimate goal is excellent tire wear, then sure dial the aligment down. It sadens me though; -2 up front and a bit less in the rear makes cornering alot more fun and won’t destroy your tires (unless you do a ton of toe).

Back to your original issue: did you drive your car on a NASCAR or circle track?? Certainly odd to hear of significant outer wear over inner.
 
Last edited:

Shmoke

ZSHAUNZ
Joined
May 11, 2015
Posts
123
Reaction score
32
Location
Lake Elsinore, CA
First Name
Shaun
Vehicle(s)
2019 Mustang GT w/PP Ruby Red
[MENTION=18542]ManBearPig[/MENTION], I share your issue, I have a 2016 GTPP and I just hit 21,000 miles. I am having the exact same issue, the front is wearing evenly, the rear is wearing on the outsides. The insides seem to match the level of my front tires. My tire pressure has consistently been at 35. I've never had any track time, simply spirited driving here n' there, and I don't have spacers. It does seem like something is wrong here.

My experience with Pzeros are not good...poor in quality in my opinion, they have disappointed me on several past Mustangs... my 2008 (blow out on side wall 1st week of ownership going 55mph on a pretty smooth road/no impact), 2012 (uneven on inside walls with a live axl, bald at 24k), and now on my 2016 (Bald on the outside walls at 20k and loud road noise). Do yourself a favor, don't buy Pirelli, they don't deserve our hard earned cash. I have tried General, Yokahama, and Continental...all of these have brands have impressed me with traction and wear compared to Pirelli Pzero.
 

Coyote Red

Well-Known Member
Joined
Oct 9, 2016
Posts
1,252
Reaction score
368
Location
Port Lavaca,Tx.
First Name
Alan
Vehicle(s)
2016 5.0 Coyote Red
Vehicle Showcase
1
I've always used 1.5 neg for a street car, R/T cars may now accept more neg camber with the new IRS as I haven't researched the PP settings for the S 550 platform. The 1.5 neg is for the S 197 platform Boss mustang.
 

KevinG

Well-Known Member
Joined
Jan 22, 2016
Posts
386
Reaction score
101
Location
Fredericksburg, VA
Vehicle(s)
'16 GT PP 6SPD Recaros w/black roof
Any uypdates ManBearPig? I am having the same issues with the rear Pirellis w/13k wearing on the OUTSIDE. Alignment was done soon after 1" lowering springs as well. ALignment results showed within spec or right on the line. Wondering if I'm wasting time/money having the car re-aligned before I put on my Continental tires on the rear... Or are the factory PP Pirelli tires just total crap and wear on the outside for some strange reason?
 
 
101 - Anderson Composites - 1
Top