B-12 pour in has instructions on the can for use in the engine. Follow them carefully & do it more than once if your engine is that bad. I put a can into mine when I did my UIM cleaning a few months ago. Now when I open the oil cap I see gleaming, well oiled parts in there.
How long have you owned your 'Tour? Try to find a free carfax & see if it was a rental fleet vehicle. Mine was, but it seems to have been well cared for.
If you've gotta do it more than once, I would suggest you put in some Valvoline oil and run the B-12 through & change the oil in two week intervals until you're happy with the condition of the engine. Valvoline runs a little cleaner than the typical engine oil, & when you're done you can switch over to Mobile 1.
