This is the exhaust cam side of a 2000 Lexus GS300 @ 90K miles with the Toyota 2JZ-GE engine. It had normal dealer oil changes at reasonable intervals until about 45K when I took over maintenance. From 45-90K it has had Valvoline SynPower 5w30 at OCIs of about 7K miles, sometimes a little more, sometimes a little less. After the dealer service (they used Denso filters), Purolator filters were used. This engine has had no additives in the oil. The intake side was equally clean.
