Overall, the U.S. Market for diesels is still anemic, with only about 1 percent of passenger cars, light trucks and SUVs sold last year so-equipped. Add full-size pickups, and you get roughly 500,000 units sold, just over 3 percent of the total.

Volkswagen is the diesel sales leader in the United States, with 14.9 percent of its passenger car sales in 2005 being diesel. Add to that the Mercedes E-class, DaimlerChryslers Jeep Liberty SUV, and various full-size pickups, and youve pretty much exhausted the diesel options for U.S. Drivers.

Meanwhile, diesel-powered personal-use vehicles hit an overall 47.6 percent Western European market share in 2005, and are forecast by J.D. Power and Associates to reach 55.9 percent by 2015. Some of this growth may be due to the fact that some European countries have tax codes that favor diesel over gasoline at the pump. This effect is illustrated sharply in Luxembourg, where three of every four passenger vehicles registered in 2005 were diesel, while next door in the Netherlands they were only 28.8 percent. Denmark and Finland had diesel registration levels of around 20 percent while France, Austria and Belgium were approaching Luxembourgs market penetration.

Detroits Big 3 are in the thick of this wave, with prominent diesel passenger car offerings – outside the United States. Ford of Britain, for example, is enjoying huge sales of its Mondeo 2.0-liter diesel model, which gets 50 mpg. Its Fiesta 1.4-liter diesel does even better, with 64 mpg in urban driving. Fords diesel/petrol mix for the U.K. market is on a steep curve, with diesel penetration growing from 11 percent of the mix in 2000, to 23 percent in 2003 and 27 percent in 2004.

Not to be left behind, in 2003 General Motors was launching the worlds first Euro IV-compliant diesel, a 1.7-liter for its Vauxhall Astra. A year later it launched a 1.3-liter diesel, the worlds smallest four-valver. In South Korea, where diesel is expected to meet half the demand by 2015, GM Daewoo has invested hundreds of millions in its diesel engine plant in the city of Gunsan, turning out a family of Euro-IV 1.5 and 2.0 liter engines. These engines are targeted to Korea and also sold in other markets including Europe.

In North America though, GM apparently sees diesel as best suited to large cars and trucks. Most of GMs diesel sales in the United States come from its Duramax 6600 truck engine, not smaller units like those it promotes in Europe and Korea. Speaking last year in Chicago, Charles Freese, GM executive director for diesel engineering, emphasized the companys commitment to diesels, but also noted that their higher up-front cost and the need to meet U.S. NOx standards (which are one-sixth that of Europe) make these engines a tough sell. Even with their fuel economy advantage over gasoline, he said, it may take years for consumers to make back the premium they pay for a diesel engine. He suggested that full-size pickup trucks and vehicles used for towing are the best bets for diesel penetration – and profits – in U.S. Markets.

DaimlerChrysler is more optimistic. Citing its plan to substantially increase its production of diesel-fueled vehicles, Chrysler President Tom LaSorda in June noted that his company had introduced its mid-sized diesel Jeep a year earlier, expecting to sell 5,000 units. We have already sold more than double that number, showing that there is growing customer receptiveness to diesels.

The most-cited reason for this growth is light-duty diesels advantage at the fuel pump. Although diesel fuel is sold at fewer retail outlets than gasoline and is roughly the same price, it promises much better fuel economy – 20 to 40 percent better, pointed out DaimlerChrysler product development engineer Christopher Engel earlier this summer.

Additionally, he said, diesel engines provide up to a 50 percent increase in power and an 30 percent increase in torque for a significant improvement in performance over a similarly sized gasoline engine.

Oil Now, Cars Later?

All OEMs are very interested [in diesel] and were working toward expanding our diesel product line, Engel pointed out.

This emphasis is reinforced by J.D. Power and Associates. While the share of personal-use diesel vehicle sales in North America was only 3.4 percent in 2005, the research firm predicted that will climb to 15.3 percent in 10 years.

Whether diesel will actually fulfill that forecast is still to be seen. But Daimler-Chrysler wants the North American lubricants industry to set the stage now, so that approved engine oils are in the marketplace when (or if) a boom comes.

Elsewhere, light-duty diesel engine oil specifications are already in place under ACEA, Europes vehicle manufacturers association, and JASO, the Japanese auto industrys trade group. ACEA has defined three catalyst compatibility oils for new light-duty diesels and has others covering older vehicles, too. In the United States, by contrast, engine oil categories are the domain of the American Petroleum Institute, which has no light-duty diesel category yet.

In June, DaimlerChrysler laid it on the line. Engel declared that his company would like API to determine the feasibility of licensing one of ACEAs diesel engine oil specifications – the ACEA C3 Sequence for light-duty diesels equipped with particulate filters and three-way catalysts – by July 7.

API met this deadline, sort of. What API decided on June 22, in the words of Joan Evans of Infineum, was to set up a work group to, establish a process, evaluating what would be in the specification and then having the Lubricants Committee making the final decision on the composition of the specification.

Chevrons West Alexander, immediate past chairman of APIs Lubricants Committee, championed the idea of a working group to move the issue forward. We are jumping the gun unless we first decide to establish a new light-duty diesel category, and then consider what should go into it, he advised. Remember, a need has already been expressed from two sources, DaimlerChrysler and ASTMs Passenger Car Engine Oil Classification Panel.

Shells Jim Newsom, the committees new chairman, voiced both caution and optimism. He said, A lot of hard work went into developing the current process for gasoline engine oils. Lets not lose that experience and start at ground zero with passenger car diesel.

Newsom received strong support from Lubrizols Lew Williams who said, We support the need for a light-duty diesel category and will be heavily involved in defining exactly what the specification should look like.

Larry Kuntschik, representing the Independent Lubricant Manufacturers Association, agreed. This is a growing market and if these vehicles are going to be significantly different from heavy-duty engines we will need this category, especially down the road in 10 to 15 years.

The discussion was enough for Engel, who said, This action satisfies our July 7th deadline. Well need a follow-up confirmation in writing.

It is often difficult to get Lubricant Committee members to volunteer for special work and task groups. Not this time. Alexander was the consensus choice for chairman, and he had to cut off membership after 15 volunteers had expressed interest. All major oil and chemical additives companies will be represented on the task group.

Detroits Approaches

Jim Linden of General Motors, who chairs the auto industrys lubricants council, ILSAC, confirmed that his group has not reached consensus on what an API light-duty diesel specification should look like. He added, While one ACEA consensus C specification is the preferred option for a new API category, a tiered light-duty specification based on all three ACEA levels, C1, C2 and C3, is also an option. Individual auto makers could then tailor a company specification to the tier that best suited their engine technology.

Ford and DaimlerChrysler have taken different stances: the latter favors ACEA C3; Ford likes C1. All three C oils are catalyst compatible, but C1 oils have the lowest levels of sulfated ash, phosphorus and sulfur (SAPS).

Fords Mike Riley made his companys case, for the lowest-SAPS version. Ford is strong in the light-duty diesel European market, and North America plans to introduce light-duty diesel vehicles in the future, he said. Late last year he described Fords light-duty diesel program to ASTMs Passenger Car Engine Oil Classification Panel. Ford North America and Europe are developing light-duty diesel engines with prototype 5W-20 and 5W-30 oils meeting ACEA C1 requirements. Ford Europe conducted fleet testing on 53 vehicles with six different engine types, evaluating prototype ACEA C1 oils. They accumulated a total of 3.28 million miles of which about 86 percent involved light-duty diesel engines and the balance gasoline engines. Drain intervals were extended up to 37,000 miles for the diesel engines and 25,000 miles for the gasoline engines to challenge oil performance under severe operating conditions.

Riley summed up: Used oil analysis from all fleet evaluations indicate prototype ACEA C1 oils with 0.5 percent ash, 0.05 percent phosphorus and 0.2 percent sulfur provide equivalent performance to ACEA A1/B1 oils with 1.05 percent ash, 0.10 percent phosphorus and 0.35 percent sulfur.

Engel offered the DaimlerChrysler view. Europe has a light-duty diesel category and a lot of experience with diesel. It seems logical to bring in their background. A minimum-standard, widely supported API service category to serve the expanding North American light-duty diesel market can lay a foundation which OEMs can build on for their own needs.

For example, he continued, we have a variety of diesel engines and applications and currently use the Mercedes Benz 229.51 specification. One possibility would be for API to put a reference to C3 inside the donut. We dont think there should be a proliferation of OEM standards.

ACEA C3 is the low-SAPS light-duty European specification. We support this specification to meet tightened emissions requirements and to improve fuel economy over gasoline engines.