I've been using Lucas for along time now...I've never been a fan of additives period....BUT
I have/do used Lucas in myTruck Diesel Engine and rears, Harley Engine + 4 speed trany and also there power steering product actually did what it said on the label. I only used it once in the Jet Boat when I had 20-50 oil in it and very hot summer temps. It did raise oil pressure at wot and cruising speeds...I prefer and run straight Kendal 40 wt. without anything else.