Interesting video from the Oil Geek

[nismou20]

I’m a Castrol guy for the most part but who knows. Valvolines commitment to research seems impressive
https://youtu.be/kyyZDghgdCI?si=87eqdmFStOchZkUb

[DAC21]

Interesting video. Impressive cleaning performance. Adequate zinc of nearly 1400ppm. Phosphorus a bit under 1200pp. To bad there is no weight higher than 5-30 in the Restore and Protect line.

[redroadster]

GMs top engine cleaner ,did this in the early 80s ,it dissolves the gum of the engine varnish ,made the best inj cleaner, but when it does it there's grit in with it and it goes thru the engine and in the 1/8 in oil passages will clog & gets in the bearings ...this was per our 2 dedicated engine techs

[Gregs672000]

I've subscribed to his site after watching one YouTube on selecting the right oil based on bearing clearance and oil temperatures. Also strong recommendations to not add ANY additives like more zinc as it can SERIOUSLY mess up the oils wear properties resulting in MORE WEAR. This guy is very science based. I recently switched to Pensoil ultra 10/30 but may go back to VR1 20/50 or 10/30. I was going to post here but wanted to do more research and see if he answered my questions to him.

[Gregs672000]

Regarding cleaning oils, this one is specifically designed to NOT overwhelm the filter, which was a problem with previous such oils. The cleaning is done over 4 changes or so. Very interesting stuff if your engines are varnished or have a lot of build up.