There is no doubt that diesel is seeing an upward trend in North America, bringing with it both opportunities and challenges for the automotive aftermarket.
It’s not that there weren’t diesel engines in the market before. General Motors tried its hand at putting diesels in passenger cars in the 1970s. Faced with the need to get its large cars off the line in a way that mimicked the way its pre-emissions-controlled engines did, its Oldsmobile division developed the 5.7L LF9 and 4.3L LF7 V8s and the 4.3L V6.
In short, it didn’t go well for the Detroit automaker: these engines were so notoriously unreliable that it essentially ruined the reputation of the diesel engine in the U.S.
Of course, there have been others all along who have continued to offer diesel engines, like VW and Mercedes- Benz, but the volume on these has always been relatively small. Here in Canada, the diesel hasn’t suffered from quite the same stigma as in the U.S., but this has almost certainly played a role in hindering the overall proliferation of passenger- car diesels in North America compared to Europe.
There have been other factors, of course, such as legislation that focuses on emissions rather than fuel economy, and the relatively low cost of fuel in North America.
Things are changing, though, and that is changing what is occurring in the economy with the price of fuels, and the technology under the hood.
It is also important to note that the ultra-low-sulphur diesel fuel required by modern, high-tech diesel engines–so-called “clean diesel”–has only been widely available for a few years.
Ultra-low-sulphur diesel fuel (ULSD) is fuel that contains less than 15 parts per million of sulphur (as opposed to 500 ppm in regular diesel). It is usually used for on-road applica- tions. Since Sept. 1, 2006, all on-road diesel fuel sold in Canada has been ULSD.
However, regular-sulphur-content diesel is still available for off-highway usage. This dyed or marked off-road diesel fuel may be regular sulphur or ultra-low sulphur. Users should ask their local suppliers about the sulphur content of the off-road diesel fuel they supply; in Western Canada, for example, all Petro-Canada diesel fuels sold for off-road use are normally ultra-low-sulphur diesel.
While in Canada a wholesale changeover to ULSD has already taken place, in the U.S., a different approach has been taken. In the U.S., regular-sulphur-level diesel is still legally sold, even though as much as 90% of fuel available at the pump was already ULSD within months of its introduction in 2006.
Also, there have been some concerns that the ULSD fuel available in North America does not meet the same lubricity standards as that available in Europe, where much of the clean diesel technology was developed, and that this may hasten the failure of certain components such as the high-pressure, direct-injection fuel pumps these engines use. Accordingly, there has been some blogging about the use of lubricity additives, particularly in winter. It is notable that fuel suppliers warn against this practice: PetroCanada, for example, states that routinely adding additional lubricity additive to fuels is hazardous, as high dose rates of some lubricity additives have been found to cause problems such as sticking of plungers, metering valves or fuel-injector racks.
This is a situation which should probably be monitored over the medium term, but the fact remains that the new clean diesel engines that have precipitated the arrival of ULSD are arriving on our roads, and service bays, in increasing numbers.
According to research firm Frost & Sullivan, even with the automotive industry still recovering from the global economic crisis, consumer focus on fuel-efficient options is very much on the rise. Further, increasingly stringent emission norms, such as CAFE and EPA regulations, ensure that vehicle manufacturers are focusing on lowering fleet average emissions and improving fuel economy.
The researcher pins some of the effect onto the fact that, while U.S. emission standards have been fuel-neutral over the years, the recent addition of a fleet-wide fuel economy average will be a major factor in how the U.S. auto industry moves forward in the coming years. To reach a fleet-average fuel economy of 34.1 mpg by 2016 and avoid paying hefty fines to the CAFE, investment towards meeting the fleet average economy is essential.
Certainly the big push to hybrids and electric vehicles has been a part of this; the surging popularity of clean diesel usage must be viewed in the context of this larger trend, and, in some ways, as a competing technology.
In comparison to those other technologies, diesel is an attractive option–despite the higher cost of fuel, engineering and after-treatment systems–because it offers better fuel economy and lower emissions while offering uncompromised driving characteristics, longer life, and a higher resale value.
Frost & Sullivan identifies three factors that are playing a significant role in the adoption of diesel: market perception, expensive after-treatment systems, and the availability of clean diesel technology, including diesel powertrain technologies such as TDI and BlueTec. While the limited infrastructure for clean diesels and expensive after-treatment systems are still minor barriers to the increased adoption of this technology, the popularity of diesel powertrains in the U.S. received a boost through recent accolades such as “Green Car of the Year” awards for the 2009 VW Jetta TDI and the 2010 Audi A3 TDI.
It should also be noted that diesel-powered cars have come to enjoy something of a “hot rod” image in Europe among enthusiasts–as in many cases they outstrip the performance of their gasoline-powered brethren.
Still, diesel will continue to face an uphill battle against hybrid and electric vehicles and their “green” image, despite offering comparable, if not better, performance and driving characteristics and delivering significantly reduced emissions over gasoline options.
Despite the challenges offered by competing technologies, however, diesel powertrain sales have been steadily growing over the past 12 months in North America.
Frost & Sullivan, once again: “An interesting indicator of the rising interest in diesel is the increased take-up rate when it is offered as an option. Although diesel sales are on the rise, hybrids still outsell them by 4:1, including the Prius and Insight, which are only offered as hybrids and make up 60% of hybrid sales. The diesel models have a take-up rate of 30%, as compared to the hybrid take-up rate of 10%.
“This higher take-up rate of 30%, a result of federal tax credits and higher fuel-efficiency requirements, is likely to stabilize at a lower rate as the market recovers. This increase in diesel vehicles also highlights the importance of emission control systems. With the diesel market poised to grow, the adaptation of emission control systems to ensure the 50-state vehicle legality is not limited to a single solution.”
From an aftermarket standpoint, the proliferation of clean diesel technology at the passenger-car level offers both opportunities and challenges in terms of training, tools, and parts supply.
Although fuel injection and particulate filters have become a standard, a single technology to treat and limit emissions of oxides of nitrogen (NOx), a key emission reduction target, has yet to be established. A variety of solutions including selective catalytic reduction (SCR), exhaust gas recirculation (EGR), or NOx absorbers (LNT) are available to treat the oxides of nitrogen. While the suitability of each technology depends on the application and on certain other parameters, it is not uncommon for OEMs, like BMW, Ford, and VW, to combine these systems to achieve the desired end result.
It would seem that no single technology will dominate. The aftermarket is going to have to come to terms with the proliferation of these technologies as they roll into their ser vice bays.