It’s not your grandpa’s diesel engine

Manufacturers gear up for EPA’s Tier 4 emission rules

Late in 1972, Bob George (then a University of Missouri ag engineer) bought two brand-new 1973 model Plymouth sedans. George put one vehicle up on blocks and drove the wheels off the other one. Then, he took the first car out of mothballs and drove it several thousand miles.

George wasn’t collecting Plymouth automobiles. But, beginning with 1974 models, all U.S. car makers were mandated to add of emission-control technology, and he wanted a stockpile of cars without this gadgetry.
In the next two or three years, several farmers may be borrowing pages from Bob George’s book. Before 2015, all non-road diesel engines (including those in farm and construction equipment) are subject to rigid emission-control standards—the so-called Tier 4 standards ordered by the Environmental Protection Agency—and some producers likely will be trading up to new machines before these standards take effect.

“Many farm equipment buyers probably will be purchasing machines ahead of the Tier 4 emission-control standards,”
said Darrin Drollinger, of the Association of Equipment Manufacturers. “Over-the-road diesel buyers did that a year or two before the requirement for emission reductions in highway equipment took effect.”

“I look for 2011 to be a big sales year for new machinery, as farmers buy ahead of Deere’s planned start with Tier 4 engines in 2012,” agreed Ron Andresen, sales manager for Sydenstricker Implement Company, a John Deere dealership at Palmyra, Mo. “By contrast, 2012 may be a bust where new equipment is concerned, but we could see a boom in late-model, low-hours used equipment.”

To start closer to the beginning, in the 1990s EPA outlined a “four-tier” program to gradually reduce exhaust emissions from non-road diesel engines. Tier 1 standards for new non-road diesels were to be phased in from 1996 to 2000. In 1998, EPA signed the final rule, introducing Tier 1 emission standards for diesel equipment under 50 hp. and increasingly more stringent Tier 2 and Tier 3 standards for all non-road equipment, with phase-in scheduled from 2000 to 2008.

Tier 1 through Tier 3 standards are met by advanced engine design, with few or no exhaust gas after-treatment devices (i.e., oxidation catalysts). In May, 2004, EPA issued the final rule introducing Tier 4 standards, which are to be phased in between now and 2015. Tier 4 standards require that emissions of particulate matter (PM) and nitrous oxide and nitrous dioxide (NOx) be further reduced by about 90 percent. Such emission reductions can only be achieved with the use of control technologies—including exhaust gas after-treatments similar to those required by the 2007-2010 standards for over-the-road diesel engines.

Incidentally, the U. S. Supreme Court ruled two years ago that EPA must regulate greenhouse gases (even without Congressional action) under the federal Clean Air Act, if the agency finds that these regulations are necessary to environmental and human health. EPA estimated that by 2010, NOx emissions would be reduced by a million tons per year (the equivalent of taking 35 million passenger cars off the road), and that by 2030, some 12,000 premature deaths would be prevented annually.

At this point, the EPA rules only apply to new equipment. Existing diesel-powered machinery is “grandfathered” in, with no requirement to retrofit emission-control technology onto older machines.

“However, it’s still unclear whether retrofit will be required in some areas, such as California,” said AEM’s Drollinger.
And, the jury is still out on how much, if any, fuel efficiency and power output may be affected by the EPA-mandated emission-control technology.

“When you add components to existing technology, there are always some changes,” continued Drollinger. “But engine manufacturers are working to make sure there isn’t a fuel efficiency or power penalty with these emission-control changes.”

“Tractor engine manufacturers have been able to learn a lot from the experience of over-the-road engine makers,” added Andresen.

Whether fuel efficiency and power output take a hit with the ordered modifications, there’s no doubt that machines that meet Tier 4 standards will cost more.

“Depending on the type of machine and its use, these standards will add to the cost of building engines,” said Drollinger.

At the time rules were published, EPA estimated a 1 to 3 per¬cent boost in the purchase price of typical new non-road diesel equipment. But as Drollinger said, much of the increase in cost will depend on the type of machine. For example, a 175-hp bulldozer that now costs about $230,000 might cost an additional $6,500 to add the emission-control equipment and to re-design the bulldozer to accommodate it.

And, there are other consequences that EPA might not have fully anticipated. It’s a bit like the doctor who prescribes a pill to counter the effects of the last pill he prescribed. For example, at the Tier 1 through 3 stages, sulfur content in non-road diesel fuel was not regulated. However, the 3,000 parts-per-million of sulfur in an average gallon of No. 2 diesel fuel plays havoc with Tier 4 emission-control features, such as catalytic converters and NOx absorbers. So, as part of the Tier 4 mandate, EPA ordered that sulfur content be reduced to 15 ppm for non-road fuel, effective next June.

Producing ultra-low sulfur diesel fuel adds 7 to 8 cents to a gallon of No. 2 diesel. But there’s another shoe to drop. The sulfur content in average fuel acts as a lubricant for an engine’s upper cylinders. By itself, ultra-low sulfur fuel does not provide the lubricity an engine requires.

As MFA Oil director of product development and lubricant sales Don North explained it, “The steps refineries take to comply with EPA emission requirements increase the cost of production, thereby raising the price of gasoline and diesel fuel. The retail price on low sulfur diesel and ultra low sulfur diesel has been the same, although most market areas have not offered low sulfur off-road diesel since 2006.

“When ultra low sulfur diesel fuel was first introduced, its lubricity was questioned. To address the issue, the federal government mandated that all ultra low sulfur diesel fuel be injected with an additive at the terminal, ensuring it has the same lubricity value as low sulfur diesel. ASTM specifications were also revised to include a maximum High Frequency Reciprocating Rig score of 520. The HFRR test measures the lubricity property of a fuel, which is vitally important to fuel injection systems. The higher the score, the more severe a fuel is on the system.”
Some engine manufacturers have recommended an even lower HFRR number of 460 or less, meaning additional lubricity additives are necessary.

According to Leon Schumacher, University of Missouri agricultural engineer, commercial lubricants are available on the market and most fuel distributors will add them at the request of the fuel buyer. Biodiesel provides the necessary lubricity, too; No. 2 diesel blended with just 2 percent biodiesel provides ample lubrication.
So, whether you hold onto the equipment you now own, trade up to a later-model rig, or opt to buy a new one with all the emission-control bells and whistles, at some point, you will be driving a Tier 4 machine. No equipment lasts forever and EPA’s rules appear to be here to stay.

Even Bob George’s second Plymouth finally bit the dust.

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