Uneven tyre wear, or not?

[chrisjl]

I just took my 4 year old car (one year under my ownership) in for its MOT and to have the air-con checked and was called back a couple of hours after dropping it off to be told that it would benefit from a wheel alignment due to uneven tyre wear on both left wheels. Foolishly I didn't ask for any evidence of the need and gave them the ok to do it.

When I got it back at the end of the day, the paperwork included the tread depth measurements : 4.4, 4.4, 4.3 for the front and 4.7, 4.8, 4.6 for the rear.

I might be out of touch, but I'd be amazed if the repeatability of the depth measurements is as good as 0.1mm. The rear being less worn in the middle didn't yield any advice to keep an eye on pressures.

Was it due some attention, or should I be protesting unnecessary work?

[Pica-Pica]

chrisjl said:

I just took my 4 year old car (one year under my ownership) in for its MOT and to have the air-con checked and was called back a couple of hours after dropping it off to be told that it would benefit from a wheel alignment due to uneven tyre wear on both left wheels. Foolishly I didn't ask for any evidence of the need and gave them the ok to do it.

When I got it back at the end of the day, the paperwork included the tread depth measurements : 4.4, 4.4, 4.3 for the front and 4.7, 4.8, 4.6 for the rear.

I might be out of touch, but I'd be amazed if the repeatability of the depth measurements is as good as 0.1mm. The rear being less worn in the middle didn't yield any advice to keep an eye on pressures.

Was it due some attention, or should I be protesting unnecessary work?

I would be pleased if the measurements were that close on an individual tyre. Those (or even worse) would not be an indication of uneven wear.
Now perhaps an alignment check may be a good thing, whether it was out or not. Did you get a full print out of the alignment before and after, and what the alignment should be? That would be my question.

[thebraketester]

You fell into the trap….

How much was the alignment? Did they give you before and after measurements?

[chrisjl]

Thanks both. It's as I thought, but I wanted confirmation before grumbling to them. The lack of before/after measurements is part of the grumble.

[ARHarh]

You could easily measure tread depth to 0.1mm or less. But I would say that if you measured a bunch of new tyres they would fall within a tolerance of 0.1mm or more, what you had there was pretty normal even wear.