> If truckers are willing to put this stuff in $75,000 motors and leave it > in there for up to 25,000 miles , it has to be good. There are a couple reasons why large diesel engines run non synthetic oils-generally. My father drives tractor-trailers and also is a mechanical engineer (I know,,don't ask.) He knows the advantages of running synthetic lubricants. He uses Delvac because #1 he always gets a spinner oil filtration system on his trucks (filters down to one micron.) #2 because Caterpillar requires you to change the oil every 25,000 miles regardless if it is a synthetic or not. When you change 6-7 gallons of oil per change along with $15 worth of filters (at least, depends on which change it is) synthetic doesn't add up. He does however run synthetic fluids in the axles and transmission. I am not saying the Delvac oil isn't a good oil, just the big truck scenario doesn't mean much. I use Delvac in my John Deere, Caterpillar forklift, log splitter, and my WR (because Yamaha wants me to change the oil every 2.5 hours-what a joke.) Louis
