Excessive tyre wear - rear outside edge

[Immortality]

Well then get a wheel alignment done and if it all checks out get them to add a touch of negative camber, it'll corner better too.

The missus VX has a little negative camber in the rear and yet no uneven tyre wear, it does have the extra toe rods. It has 225/50/17's on the rear @ 38psi.

Another question, what sort of load do you carry? If you do have weight in the rear make sure that is also in the car when you get a wheel alignment done otherwise it will never be right for how you drive the car.

 

[saroadie]

I took 3 measurements. Inner, middle and outer groove. Inner one is the same as the middle one. Only outer one on both sides is about 2mm less than the rest of the tyre

Sounds like a SLIGHT alignment problem then. If you haven't already done so find a good alignment operator. They can take readings and make a small change to correct the issue. Using the camber and/or toe adjustments, a pro will use side slip reading as well to optimize the car to your preference. My guy even simulates the most common load condition and aligns it loaded, this way it's spot on going down the road, not sitting in the shed. This only makes a tiny difference to the readings on the aligner but there is a difference. Takes time to do but IMO worth it. Especially if the car isn't driven by an unsympathetic, pothole seeking gutter rider.
Edit, spelling, only s in adjustments is at the end.

 

[Ron Burgundy]

Well then get a wheel alignment done and if it all checks out get them to add a touch of negative camber, it'll corner better too.

The missus VX has a little negative camber in the rear and yet no uneven tyre wear, it does have the extra toe rods. It has 225/50/17's on the rear @ 38psi.

Another question, what sort of load do you carry? If you do have weight in the rear make sure that is also in the car when you get a wheel alignment done otherwise it will never be right for how you drive the car.

80% of the time just me in the car...
No load...

 

[426Cuda]

I took 3 measurements. Inner, middle and outer groove. Inner one is the same as the middle one. Only outer one on both sides is about 2mm less than the rest of the tyre

As VC says. Its not low pressure causing the wear.

 

[greenacc]

80% of the time just me in the car...
No load...

Tyres would probably wear more evenly if you carried 100kg of sand bags in the boot to compress the rear springs and keep the tyres square to the road. If a proper alignment doesn't solve it you can try that next

 

[vc commodore]

Tyres would probably wear more evenly if you carried 100kg of sand bags in the boot to compress the rear springs and keep the tyres square to the road. If a proper alignment doesn't solve it you can try that next

Hummmm, still got to align the car as you would normally drive it....ie with or without a load in the back of the car, so how is this going to help?

 

[vc commodore]

I took 3 measurements. Inner, middle and outer groove. Inner one is the same as the middle one. Only outer one on both sides is about 2mm less than the rest of the tyre

I'll actually stick my neck out and say it actually had too much toe on the rear, providing it is both rear tyres that have this problem....If it is one side, I'd say it is a camber issue....And yes, camber and toe are adjustable in the rear of a VF Commodore.

And yes, others may disagree with this, but generally with camber, only 1 side is effected with wear issues, where as toe effects both sides.

I will be interested to see what the report comes back like, once an alignment has been done, just to see what was the cause of the problem