Auto Service World
Feature   May 1, 2005   by Jim Anderton


As emission controls get tighter, advanced technology is chasing pollutants down to the part-per-million

It’s tough to love cars these days. The entire automotive industry is under assault from the environmental movement and the mass media, with the current debates over implementation of the Kyoto Accord adding fuel to the fire. As the repair aftermarket knows, however, cars and light trucks aren’t just cleaner today, they’re much, much cleaner with a new model emitting roughly five percent of the pollutants of pre-emissions vehicles of the early ‘Seventies. And they’re going to get cleaner still, thanks to initiatives started by California’s Air Resources Board, whose auto emissions standards are copied by several U.S. states and may soon be implemented in Canada.

The acronyms for the future are “ULEV” and “SULEV”. ULEV, or ultra-low emissions vehicles have been mass produced for several years and are now entering the aftermarket repair stream in significant numbers. OBD-II and modern diagnostic equipment, plus adequate training are proving sufficient to cope with this level of technology, although software issues with OEM information lockout may yet become a problem. ULEV vehicles are a major step forward from standard low emission technology, with reductions of 70 percent for CO, 45 percent for NOX and up to 90 percent for particulates.

The next level, Super Low Emissions Vehicles, or SULEVs will reduce emission by a factor of four compared to ULEV, and will look different under the hood. Production SULEV technology debuted in 2000 with the California-spec Nissan Sentra CA, with Honda also manufacturing gasoline cars to the specification. The spotlight on SULEV, however, will likely fall on hybrid vehicles, which use smaller internal combustion engines for a given vehicle weight and performance; lower fuel burn is a good first step to lower emissions. Hybrids aren’t the only route, however. Volvo, the pioneer in feedback mixture control in the ‘Seventies has developed California-spec Partial Zero Emissions Vehicles (PZEV) with HC emissions less than one thousandth the level of pre-catalyst cars.

Volvo’s low emissions engine technology is typical of the approach that may become standard for all light duty vehicles in the future. Control software makes it work, primarily by reducing emissions during starting and warm up, and by essentially eliminating evaporative emissions.

Computerized control of the engine’s intake and exhaust valves is used to manage emissions during the vehicle’s cold start routine. First, the opening of the intake valve is delayed, which enhances the air/fuel mixture and enhances stability during combustion. Second, the combustion process is run very late, burning up fuel on the cylinder wall and reducing HC and NOx emissions. Third, the exhaust valve opening is delayed, bringing the hydrocarbon-rich exhaust gas “residual” back into the cylinder, further reducing HC emissions. Also during start-up, the car is run with a lean mixture, heating the gas in the cylinders and quickly lighting off the two catalysts. Volvo’s engineers developed an evaporative emissions control system that uses two different canisters to trap the evap emissions. One canister sits close to the fuel tank and contains three chambers filled with activated carbon. Downstream from the first canister sits another called the Hydro Carbon Scrubber (HCS), which contains a honeycomb structure coated with activated carbon. Like conventional carbon canisters, once the car is running, the trapped emissions are sucked out of the canister and burned in the engine.

Where do we stand?

Auto emissions in Canada have long been a case of follow the leader, in this case, US federal standards. In late March, however, Natural Resources Minister John Elford revealed a plan under the Kyoto-driven CO2 reduction priority to follow California’s stricter emissions standards. The Kyoto accords require reductions in greenhouse gas emissions to about 6% below 1990 levels by 2012. But emissions in Canada have increased by nearly 20% since 1990, making the target difficult to achieve without significant economic impact. On the automotive side, Canada and California are similar in their light duty fleet size, each of which contributes about 1 percent of greenhouse gas emissions globally. The agreement with Canada’s auto industry, however, measures tailpipe emissions reduction in tons, specifically 5.3 million by 2010, requiring either a 25 percent fuel economy improvement in Canada’s vehicle fleet or some reduction in industrial emissions. The Minister stated that voluntary standards would be followed by regulation if the companies fail to comply. With the currently unstable political situation in Ottawa and the Conservatives’ wariness of the Kyoto process, even these standards may not come to pass, but for the repair aftermarket, wholesale adoption of California emissions standards means tighter CO, HC and NOx levels, with some vehicle technologies that may be different from U.S. federal vehicles, as is the case now in California. California law requires automakers to release emissions-related repair information for 1996 and newer model vehicles, but the Minister has announced no similar plans for Canada.

Gasoline sulfur content critical

Sulfur in gasoline is a major barrier to achieving SULEV and ULEV emissions standards. U.S fuels, especially those sold in designated high pollution areas and in California-standard states sell gasoline with very low sulfur content, and this year in Canada, new federal regulations took effect that significantly reduced sulfur levels. The Regulations set limits on the amount of sulfur in gasoline produced, imported or sold to an average level of 30 mg/kg with a never-to-be-exceeded maximum of 80 mg/kg. On July 1, 2002, the level of sulfur in gasoline was limited to an average level of 150 mg/kg; and starting January 1, 2005, the annual average level of sulfur in gasoline was limited to 30 mg/kg. Clean fuel won’t be an issue, but water, unauthorized additives or rust will likely become more important as failure causes.

The impact on independents

Green technology is interesting, but what will be the impact when it reaches the aftermarket? The answer depends much on political considerations like I/M wear limits, and also on a little-known part of the emissions regulations. Automakers can earn NOx credits by extending the certified emissions system lifetime to 15 years or 240,000 kilometers. If this becomes commonplace, a significant portion of a vehicle’s engine systems could be warranty work for much of the vehicle’s lifetime.

Once SULEV and PZEV vehicles reach the independent’s bays, cleaning up out of spec vehicles will be more complex that current technology requires. At the PZEV level, for example, outgassing from tires and paint can be a significant proportion of evaporative emissions. Bodywork, undercoating or rustproofing, and even windshield washer fluid could be factors in future emissions tests. California, for example, already has a standard for windshield washer fluid volatile organic compounds, or VOC’s. At extremely low emissions levels, coolant or oil in the combustion chambers will kill emissions at any level, and many fuel system additives may be impossible to sell for the same reasons. Evaporative emissions is a major part of the new technologies, with many using multi-layer blow molded fuel tanks and computer-controlled purge cycles to keep the volatiles out of the air. Would a “white box” aftermarket fuel tank be made of the right materials to contain the vapour? Who’s responsible if it doesn’t? Another example is the use of Premair coatings on engine radiators to reduce ground level ozone. Although it’s a passive (not engine related) technology, will techs be able to install conventional replacement radiators? In a conventional shop environment where an oil rag could set off a monitor it may be impossible to test sealed evaporative emissions systems in the future, reducing I/M to a DTC scan. In that case, access to OEM data will become as much an environmental issue as one of rest
raint of trade. On the Kyoto front, the good news is that CO2 is not an issue of emission control technology; it’s simply a matter of better fuel efficiency. A scary future? Not necessarily. Canadian regulations might not adopt California’s standards across the board, and even if they are the phase in period may allow aftermarket equipment manufacturers to invent the shop tools needed to make part-per-million testing as common to future techs as wiping a dipstick. But with thousands of low emissions vehicles coming off warranty across the country, the time to think about tools and training is now.

Current Canadian Light Duty Vehicle Emissions Standards

The new exhaust emission standards using the conventional Federal Test Procedure align with the future U.S. standards, commonly referred to as the U.S. Tier 2 emission standards. Manufacturers certify every vehicle to one of eleven “bins”, each of which contains standards for NOx, non-methane organic gases (NMOG, commonly “hydrocarbons”), CO, formaldehyde and PM (particulate matter) as presented in Table 1. Formaldehyde and NMOG are newly regulated under the Regulations, although NMOG limits effectively replace previous non-methane hydrocarbon standards. The manufacturers’ choices of bin within which to certify each vehicle is limited by the obligation to comply with the fleet average NOx emissions standards described in the following section.

Bins 9 and 10 are only available during the 2004 to 2006 model years for light-duty vehicles and light light-duty trucks and up to and including 2008 for heavy light-duty trucks and medium-duty passenger vehicles. Bins 8 through 10 contain additional temporary, less stringent standards for certain pollutants and for certain vehicles. Bin 11 is only for medium-duty passenger vehicles and is available up to and including the 2008 model year. Beginning in the 2009 model year, applicable standards are limited to bins 1 to 8 for all light-duty vehicles, light-duty trucks and medium-duty passenger vehicles.

The Regulations establish fleet average NOx emission standards for the 2004 and later model years. The objective of the fleet averaging provisions is to create a regulatory framework that will achieve a Canadian vehicle fleet emission performance comparable with the U.S.

Each new light-duty vehicle, light-duty truck and medium-duty passenger vehicle is required to be certified to a “bin” containing specific emission standards for NOx and other pollutants. Based on vehicle sales from each “bin”, a company calculates a sales-weighted “fleet average NOx value” for each model year. The emission bins, fleet average NOx emission standards, timing of phase-ins and methods of calculating fleet average NOx values are consistent with the U.S. Tier 2 emission program.

When the standards are fully phased in (i.e., in 2009), a company’s combined fleet of light-duty vehicles, light-duty trucks and medium-duty passenger vehicles will be subject to a single fleet average NOx emission standard of 0.07 g/mile, corresponding to the NOx standard in bin 5. A company can, in any model year, generate NOx emission credits by achieving a fleet average NOx value that is lower than the standard. These credits can be used in a subsequent model year to offset a NOx emissions deficit (the fleet average NOx value exceeds the standard). A deficit must be offset no later than the third model year following the year in which it is incurred. NOx emission credits may also be transferred to another company. There are provisions identical with the United States, to promote the early introduction of cleaner vehicles or more durable emission control systems. Additional NOx emission credits can be earned by, for example, certifying vehicles to bins 1 or 2 during the model years 2004 through 2005 or by certifying vehicles to an extended useful life of 15 years/240 000 km.

Source: Canada Gazette, Vol. 137, No. 1 – January 1, 2003

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