I gotta tell ya, I've been using this stuff for about 2 months. I was concerned about the low sulfur fuel lubricity issue and after readings Spicer's fuel lubricant report I thought I'd give it a try. The results are remarkable. Before using it, if I let the truck idle for an extended period, it would run like a gasser with fouled plugs for a little while and puff black smoke on each miss. I thought about replacing the injectors to resolve this as they are original(152k miles). Honest ***** this truck runs like I DID replace them. Starts better too. Try it you will like it!