Had to replace a leaking valve cover gasket on my wife's 2002 Subaru WRX w/ 91k miles, so of course I had to take pics of the valve train and upload to BITOG. It has had synthetic oil since 9k with the last 50k or so using Redline Oil, usually around 10w30 (We live in San Diego). Overall I would say it is definitely clean although I was a bit disappointed by the varnish on the inside of the valve cover, but it may be due to the air-oil separator. Not a drop of sludge or noticeable varnish on the valve train. I know Redline is believed to have mystical cleaning abilities, but I don't think PU/PP/M1/GC would have looked much different. Thoughts?