I've been fiending, stalking this 0w-20 weight of QSUD ever since I had good seat of the pants results with a 10w-30 version of it (read: good NOACK so less heat and added ponies, as a result?) The problem arose when that older engine started seeping oil while this oil was in service. I wonder if the 0w-20 is just plain better cause the better base stock nature prevents in from consuming? Maybe different engine design curbs it too? The plot is always thick here.