Strange tyre marking...

[CJG1]

Hi there, hope this is the right place to post.

I have a 2011 Polo TDI on 17” Borbet wheels fitted with 205/40 Dunlop winter tyres (manufacture date 5211). Today when I parked the car up today I noticed on the front right tyre there’s a “line” which goes all the way around the center of the tyre. None of the other tyres have this so I’m a bit worried. Is this normal?

Here it is:


and this is what the others look like:


Tyres all have around 5mm of tread, and performed well in the recent snow.

[GreenV8S]

The top tyre has a lot more tread than the bottom one. How many miles has it done? If it's nearly new I suppose that might be a flaw in the original moulding which hasn't been worn back yet. A bulge like that in a tyre which was part worn would frighten me because it suggests a structural failure within the tyre.

[Peanut Gallery]

I had that same center line all the way around my tyres, they were there when brand new, and still there 100 miles later when the tyre was binned after being driven when flat.

They do wear away eventually, I would not worry about them at all, it is just where the tyre mold joined up.