My air compressor gets a lot of use in the summer month especially, and is now over 30 years old. Still pumps pretty good, but is seemed to be getting kinda "knocky". Kinda seemed like the rods might be getting a little loose. I have never run it low on oil, or with excessively dirty oil, but like I said, it has a lot of hours on it. So anyway, I decided to see what would happen if I used some of the lucas that I just happen to have sitting on the shelf for a long time. I mixed it about 25% Lucas to 75% #30 ST oil. Has only been a couple days now, but I do have to say it is noticeably quieter now. I also put some (50%) in an old B&S 5 hp. h.s. on a tiller that sounded ok, but smoked quite a bit. Didn't help the smoking at all, but when I pulled the head and side cover off the engine, and took the rod cap off to pop out the piston to re-ring it there was a really slick coat of oil/lucas on the rod/crankshaft . Now don't get me wrong I wouldn't think of using the stuff in a good engine, but I seriousely believe that in loose/worn equipment it will make things last a lot longer. Just my observations and 2 cents worth