I really am partial to shell products( My Dad had 3 shell stations back in the 70's and 80's)and want to change my oil back to a sopus brand. I have been using redline 5w30 and it did quiet the engine down initially until i heard some pretty loud tapping and pulled the rocker trunnions apart and noticed petty bad wear and replaced the caged roller bearings with bronze bushings and it is much quieter now. 2008 z06 basically stock with headers and no cats. so i dont have to worry about hurtng them with the wrong oil. I deleted my oil cooler and my oil temps reach temp pretty quickly and run real close to my coolant temps (200-210) Thanks alot for any input.