I have come to the realization that the big auto companies and the auto repair shops are running a BIG scam....and it's costing us people a lot money! I haven't changed the oil in my pick-up for over 60,000 miles, and guess what? It still works great! I have saved a few hundred dollars by not getting the oil changed with NO negative results. I recommend that everyone stop wasting money on oil changes. And while you're at it, I've found that it's a waste of time checking the oil level in the truck, too. P.S. I was wondering if there are any kinds of additives I could use in the oil to make it last even longer? What about yeast?