I consider this as a temporary fix, and it may not be for every situation, but thought I would share it. My 560sel has this oil comsumption problem as well - about a quart every 500 miles, until I tried using Lucas Oil stabilizer. Oil consumption is now about a quart every 1500 miles. I guess there is not much pressure up in the valve cover area that this additive is able to slow down the leak past the stem seals....