mis3

When I changed the front tire rods weeks ago, the mechanic told me that my 2 front tires were "cupped". I had no idea what this meant and the mechanic showed me. When I ran my hand across the tire on the thread, I could feel the surface was not smooth. It kind of went up and down slightly.

When I drive in very low speed, I can feel the tire not being smooth against the road. Also they are quite noisy.

These are my winter tires, Toyo Garit KX. This is my 3rd winter with these tires. I checked the thread wear and they are still good.

What would cause this?

Glyn M Ruck

Cupping & feathering is caused by wheel alignment issues. The Benz standard alignment tends to cause a little of it anyway. Certain tyres with big block tread designs are also more inclined to cup & feather. This causes air pumping noise & vibration.

mis3

Not sure how my tires would become this way. My alignment seem Ok in the sense that the car would go straight while letting go of the steering wheel. Also, the threadwear of the tires are even. my only complaint is the vivration at low speed, like in 10-20 MPH.

This set of Toyo is much better than the previous winter tires, Pirelli Snowsport 210, in snow driving. Not sure if these Toyo are cosnidered big block tread designs.

Is it safe to drive on these tires? Will driving in these tires hurt other components?

Glyn M Ruck

I've had a look at that tyres tread & it's broken block structure which makes it good in snow is going to be more inclined to feather & cup.

It is a unidirectional tyre so you can't change it's rotation which would partially mitigate what is happening.

Short of skimming them you are going to have to put up with it or change for new.

It's safe to drive on them as long as the vibration does not become excessive.