ok my friends car eats through oil like a **** but when the sparks are removed thier clean, i know running rich turns them black, blue smoke indecates burning oil but his smoke is more black so anything else too look out for? no leaks around the engine by the way!

 

pull your plugs and find out ....

 

Engines eat oil for many reasons. But just because the oil is black does not mean it only rich. I've had a motor put out black smoke before, and it was oil and a little rich. Not really rich. Check the compression on the motor and do a leak-down test to see what the rings and head are doing. That might tell you more.