Iv always been a castrol guy myself. In my 87 mustang before I replaced the engine that had about 220K miles on it. I was running castrol high mileage. When I removed the heads and checked out the main on the original engine there was no build up or gunk once so ever I'm sure I could have rebuilt that engine and had no issues but I got a deal on a build block. I had gotten the mustang around 150K miles and beat the living crap out of the motor, I was 15-21 years old having that car and you can only imagine what kinds of things I did to that poor engine. It had small bit of blow by at the end of its life so I wanted a transplant and so got a bored engine better pistons and bigger heads. In all I ran the castrol high mileage from the day I got it and after each night at the local drag strip I would change the oil and that engine turned out to be good when I replaced it. That's just my experience and have gone with that oil since that day.