calhoon

Just a quick comment on engine oil getting black. A few years ago, while attending a GM lubrication school this topic was brought up. The instructor told us if the oil wasn't getting black it wasn't doing its job. A good detergent oil should keep all of the soot etc. in suspension so it can be filtered and drained out. My used oil annalist has shown my oil to still be good at 20,000 miles even if it was black. Black is GOOD!