150,000 miles. Before the valve repair, it was using less than a quart every 1,500 miles. It's mysterious, and maddening. It's obviously burning oil. There's soot in the tailpipe, but no smoke whatsoever after the first 1/4 mile, and about half the drives, no smoke at all. The oil viscosity seems thin on the dipstick, and there is the ever-present smell of gasoline.There is no way it’s burning that much oil without having worn rings. How many miles?