I use bleach white and a soft scrub brush if my tires are really dirty - or I want to get old tire dressing off. Also works wonders if you have white letter tires or white walls J/K.

 

Bleach white works great on tires. Meguiars and eagle one wheel/tire cleaner work good too. Let it sit a minute then hose it off then wash your wheels/tires with soap and water. I use black magic tire dressing to shine them up. Apply it to an applicator instead of spraying it on your tires. It leaves some brown residue but I usually wash my car often enough that I clean it off before it leaves the residue.