My brother who has been a professional mechanic for 25 years, recommends Mobil 1 Extended Performance oil. My dad, who has been an avid Havoline and STP fanatic all our lives, also uses and recommends Mobil 1 Extended Performance. I've been using it in my turbo charged Volvo, my normally aspirated Saturn Sky, and my daughter's Honda Civic for over 2 years, changing the oil and filter at 10 -15,000 mile or 1 year intervals. I am a fanatic about my cars and only want what is best for them. (I was unaware until today that Mobil 1 had filters, so I've been using another premium brand.) The oil is very black which tells me it is doing a good job of keeping my engine clean, and it still runs out thin when draining. Also, after changing the oil, on first start up, there are none of those few seconds of engine clatter waiting for the oil pump to refill and pressurize like there is with conventional oils, indicating that the oil has left a protective film in my engine. I'm impressed. I do have a question; my Saturn Sky (no turbo) has always had lots of valve clatter. It may be normal, I don't know. It currently has 75,000 miles on it and there is no valve adjustment on this engine. Would Mobil 1 High Mileage help with this? It's a high revving engine so I don't want to do the wrong thing.