Posted by David Sherman on Monday, April 28, 2008 at 12:06:23 :
In Reply to: running diesel engine on used oil and other free stuff posted by David N. Lundstrom on Monday, April 28, 2008 at 10:34:26 :
I've heard many fleet people say they use filtered waste oil at a ratio of no more than 10% in ordinary diesel engines with no problems. I burn all kinds of stuff in my multifuels, but they're made for it. Some say ATF is actually good for a diesel engine, improves the lubricity that's lacking in the new ultra low sulfur fuel. Some big fleet operators have a fairly elaborate filtering apparatus for cleaning the used oil. I'd be leary of just pouring it in as-is, though that's what I usually do after letting it stand in a bucket for a few months to settle. I rigged up a pump and filter to clean a couple barrels of very old furnace oil, so maybe I'll pour the motor oil in with the old furnace oil so the filter will take care of both of them. One guy, retired from a large contractor, told me using the old furnace oil should be fine if I change the filter every 100 gallons. I have a case of the filters, so that's no problem. It occurs to me that there are a lot of people with oil tanks in their yards that they forgot about years ago when they switched to natural gas for heating. Some of those tanks probably still have a lot of oil in them. I wouldn't want to risk it in places with strict environmental enforcement, or with people I didn't know, but if you have a friend with oil in an old tank, they might be glad to be rid of it, and you could filter it and use it. There's probably several inches to a foot of sludge and water in the bottom of the tank, but you might be able to get some good oil off the top.