Sumitomo is a Japanese manufacturer of many things and tires happen to be one of them.
The reason you don't hear about them much is you will not see "Sumitomo" on the side of a race car or notice them sponsoring a team. They also do not run any television commercials. Are they good tires? They offer many tires that provide a great value for the dollar.
Sumitomo recently introduced a new Grand Touring All-Season tire, the HTR Enhance L/X. It offers a very nice ride and includes an exceptionally generous treadlife warranty. The tire features a 5-rib asymmetric tread pattern that blends stability with even wear. Initial feedback has been favorable for this tire and testing will take place next year.
When it comes to summer tires, the Sumitomo HTR Z II and HTR Z III are favorites. They have very good street capabilities and great customer feedback. Both tires are popular with drivers who are seeking a summer tire that enhances the appearance of their wheels and vehicle.