Funnily enough, I just found a mix I'm very satisfied with - Vallejo Black mixed with Vallejo Dark Grey at a ratio of about 4:1. The paints are naturally quite matt, but my thinning mix also has a touch matt medium mixed in which knocks it back. The below pic (albeit a bit poor) shows the tyre colour vs Tamiya's Satin Black (X-18).
The key, however you do it, is to aim for a charcoal or off-black, and to matt it down so it isn't shiny. Rubber is naturally matt and generally isn't a pure black (especially after use).
I should also say - airbrushing (as above) gives the most convincing effect, but these paints do thin and cover quite nicely so you may still have luck doing it by brush