I was on plan to go back to Lucas Oil treatment, what I started with, and heavier oil.
It seemed to make sense at the time.
But then I went to you tube too look for advice and there was Scotty saying how important it was that you stay with the specced oil for your engine.
Here’s the video link.
What he is saying makes sense. I’ve heard the prevailing wisdom of the old days growing up, which he addresses, but he brings us up to the present day where he discusses new engine technology and the oil requirement for these new engines. The oil specced on the Yukon is 5W-30, So I guess it doesn’t make sense to go above this.
So on the Yukon the oil specced is 5W30.
So it’s going to be either the lighter Lucas Oil treatment, or some other product made for hydraulic oil lifters.