My best friend works for a heavy equipment company. The only oil they have to use is Delvac 5w-40 synthetic. The owner has a completly restored 1956 Ford. It is the one with the retractable hardtop. The owner was changing his own oil and after draining it got called away.He came back an about an hour later and cranked the car. It started ticking after a few minutes, but he kept it running. He called my mechanic buddy over to listen to the new noise, he said that the noise was different than a lifter tick or rod knock, and told the owner he would try to figure it out before he left for the day. The motor has now been idling for about 30 to 45 minutes according to the owner, he looks and sees the oil jugs sitting where he had originally left them still full. He shuts the car off, fills the crankshaft, cranks the car and the ticking slowly subsides. He drives the car around the block a couple of times and all the noise disappears. The engine never seized and it seems at this time all is well. I use this oil in my Miller Trailblazer welder with a 20 hp Onan because of what I have read here. I was a believer and now my buddy is a true believer also. The boss must have been a believer because that is all his company will use in all of their equipment large and small. I bet he is happy with his choice. GOOD OIL under tough circumstances. I promise this is true, because I type so slow it would not have been worth the effort to lie. I use Mobil Delvac 1300 15w-40 in my Powerstroke.