Know of nothing contrary to the 6 quarts, but in the many oil changes I have performed on mine, I have noticed from time to time 6 quarts will overfill it slightly and I always siphon all the oil out of the filter canister as well. ~ 1/2 quart over probably not a problem. But be very sure the high mark on the dipstick is not coolant in the oil from a faulty head gasket. The oil, of course, would be muddy looking in that case.