Diesel Cleans Up New Low-Sulfur Fuel Means Changes in Both the Engine and Oil
Written by Steve Temple
That old song by Bob Dylan about the times they are a changin' is more apt than ever, especially for owners of diesel-powered vehicles. As of June 2006, low-sulfur diesel fuel began flowing through nation's pipelines. (Due to the volume of fuel already in the system, however, it will take a few months to appear at all retail pumps.) The EPA now requires a 97 percent reduction in the sulfur content of highway diesel fuel from its current level of 500 parts per million (ppm) to 15 ppm. The benefit is a cleaner environment-but at a price. The EPA estimates that this new diesel fuel will cost an additional four to five cents per gallon to produce and to distribute.
On the other hand, the EPA points out that once fully implemented, this change will not only enhance environmental protection, but will also prevent nearly 8,300 premature deaths and tens of thousands of cases of respiratory ailments such as bronchitis and asthma.
Looking forward, Ultra Low-Sulfur Diesel (ULSD) enables the use of modern pollution-control technology found on 2007 engines to meet the new EPA Tier 2 emissions specifications that will be fully in force at the end of this year.
What does this mean for owners of 2007 and later model year diesel-powered highway vehicles? They must refuel only with ULSD fuel. However, owners of 2006 and earlier model year diesel-powered highway engines and vehicles may use either ULSD or Low Sulfur Diesel fuel during the transition period. Only ULSD fuel will be available for highway use starting on December 1, 2010 in states covered by EPA emissions regulations.
California regulations call for a more aggressive implementation of ULSD, with all highway diesels required to be ULSD by September 2006.
What if you don't use the new fuel? Improperly fueling a 2007 and later model year vehicle with Low Sulfur Diesel (LSD) not only can permanently damage the emissions system and void the warranty, but also is illegal and punishable with civil penalties. Just one tank of low-sulfur fuel in a '07 engine impacts both the operation and warranty of that engine, so don't even think about using anything other than ULSD. The nozzles are the same, so you'll have to look carefully at the label on the pump to make sure you're using the right stuff.
Related to these changes in diesel fuel are changes in diesel engine oil as well. For instance, Shell Lubricants has announced the development of a new formulation of Shell ROTELLA T motor oil. The new formulation meets all of the specification criteria for the new API CJ-4 service category for diesel motor oil, as well as the requirements of the low emissions engines of diesel engine original equipment manufacturers (OEMs)
A critical feature in the CJ-4 category is its compatibility with 2007 emissions devices such as a diesel particulate filter, which requires the use of both new fuel and new engine oil.
In addition to meeting the new emissions requirements, Shell says its motor oil can also provide performance benefits when used in engines built prior to 2007. While you can still use CI-4 with the new ULSD fuel in pre-'07 engines, Shell points to several advantages of its CJ-4 oil, such as improved oxidation control, significantly less engine wear (50 percent or more), along with reduced soot and deposits.
The bottom line for diesel owners is that a '07 engine will run much cleaner, with no more soot or stink, but you'll need to make sure you're using the right fuel and engine oil. Older engines probably won't be affected all that much by the new fuel, and you can keep on using the same oil as before, but there some good reasons for switching to a newer formulation. So while the times they are a changin', it all depends on what you're drivin'.
