Maybe it associates their name with high quality as well.

It helped them sell more tires, it associated the tires name with higher quality, it made money by itself, and it pushed the mascot into an icon capable of making money by itself.

All for something that sounds like a dr. Doofenshmittz plan.

You have to remember that Michelin is a French company, so the Michelin star guide was originally about getting the French public to drive to French restaurants.

They make a bunch of money selling the guides.

It’s become a whole side business.

I would think it would be really hard for them to tell if it's working or not, but at this point the restaurant ratings are kind of their own institution and there would probably be a backlash if they shut it down.

The state/county/province/whatever pays several million dollars for the guide to judge its restaurants.

Its a very valuable tourism and service industry development tool.

Shrugs. I have never eaten at a starred restaurant and I have never specifically purchased tires from Michelin.

The cost of eating in the finest establishments in the world, together with hotels, air-fare and double blind secrecy makes that it's a net money sink.