I once ran Penrite ten tenths full zinc 10w 40 in my L77. It didn't like it at all. I went straight back to Penrite Enviro Plus 5w40 and it loved it. Still does. 90,000k's, with plenty of tacho romping and redline gear shifts and it's still quite as a mouse.
Ahh ok,what do you mean it didnt like it?
Does your 6.0 have piston slap?
Well maybe i wont run it then,my tuner actually recommended 15/50 ten tenths.
He was telling me the reason the roller tips on the lifters fail over time is because of the thin oil causing the oil film to be too thin and causing the roller to slip on the cam,all new to me.
Dont quote me on that because it is all his words,i know sweet fa about that lol.
Id love to know what oil toyota put in when i bought the wagon from them,ive not had a single issue with the oil they used,might look into it.
Spoke to toyota and they used mobil 5w30 formula s which to the best of my knowledge is semi synth,motor runs great with no noise and dosent burn any oil.
Pretty sure it only comes in 205 drums so maybe a workshop special oil lol
Might just try penrite enviro+ gf 5w30 and see how it goes,penmrite recommend it for the 6.0,it runs fine on 5w30 so i dont see the need to change it to a thicker oil yet.