Did you know that "red" or "farm" diesel fuel can hurt the engines in your vehicles? Departments that are currently taking advantage of an exemption to use this lower-cost fuel should switch to regular diesel now.

Red farm diesel is just a high-sulfur #2 diesel with a red dye to identify it for purposes of taxation. It’s intended for use in farm equipment and other off-road vehicles. The dye won't hurt your engines, but the sulfur content can. During the combustion process, the sulfur forms sulfuric acid, which can damage engine parts. Fuel formulations differ with each producer. Generally, the cheaper the fuel, the higher the sulfur content and the more potential for damage.

Looking ahead, engines designed for 2007 and beyond can't use high-sulfur fuel at all. In fact, they can't use the current low-sulfur fuels either. They will need ultra-low sulfur diesel fuel. Most wholesale and retail fuel outlets will probably change to the ULSD by the end of 2007 or sooner. Farm diesel may become scarce or disappear entirely.

This feature offers a variety of short tips and facts about apparatus maintenance and testing. Look for it every month. Submissions of 150 words or less are welcome from our readers, subject to editing. Send them to In Service Senior Editor Chris Cavette at cavettes@ix.netcom.com.