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Emissions Regulations - Part Two

The latest emissions standards in Australia...

By Michael Knowling

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At a glance...

  • Final of two-part series
  • The adoption of cat converters and unleaded fuel
  • Current emissions standards for new cars
  • Ongoing emissions checks
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In the first part of this series (See Emission Regulations - Part One) we looked back at the first major emissions regulation to challenge Australian car manufacturers – ADR 27A.

In this, the final part, we’ll examine how local manufacturers managed with the introduction of catalytic converters, unleaded fuel and the current Euro emissions standards. We’ll also look at ongoing emissions checks – issues that are directly relevant to you!

The ‘80s, Cat Converters and Unleaded

From February 1st, 1986 all cars manufactured in Australia must be fitted with a catalytic converter and run on unleaded fuel. This was introduced as federal law under ADR 37.

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Fitment of a catalytic converter serves to dramatically reduce toxic exhaust emissions. Cat converters contain a ceramic honeycomb that has a very fine coating of precious metals. Upon contact with exhaust gasses, these metals reduce toxic emissions as well as transform hydrocarbon and carbon monoxide to carbon dioxide and water. Oxides of nitrogen are also dramatically reduced. The downside is that a cat converter causes an increase in exhaust backpressure, which slightly reduces power and fuel economy.

But the biggest problem facing local manufacturers in 1986 was the cat converter’s incompatibility with existing leaded fuel.

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Unleaded fuel became essential to ensure effective long-term cat converter operation and, secondly, to eliminate airborne lead emissions. The switch from leaded to unleaded fuel rushed local manufacturers to find ways to protect their engines from exhaust valve and seat damage (lead was previously used as a form of lubrication for valve sealing). Another problem was finding a way to maintain a relatively high power output in the face of dramatically lowered fuel octane – leaded fuel ranged between 95 and 99 RON while the new unleaded fuel was just 91 RON. As a result, engine detonation was a major concern.

So what did local manufacturers do?

Ford tuned its existing cross-flow 4.1 litre engine to accommodate unleaded fuel and, in the process, lost 5.5kW and 19Nm. The 1986 Falcon XF 4.1 produces just 97.5kW and 297Nm at lower revs than previously, while a more upmarket EFI version put out 121kW and 325Nm.

Holden took a completely different approach to Ford.

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Instead of reworking an existing engine, Holden took the drastic action of employing a Nissan-designed 3-litre six cylinder for its popular Commodore line. Interestingly, the Nissan/Holden SOHC 3-litre used multi-point EFI and, despite running unleaded fuel, produced 114kW – a 33 percent leap over the previous 3.3 litre engine which chugged out just 85kW on leaded fuel. And then Holden released the turbocharged version that pumped out a massive 150kW on unleaded without the aid of an intercooler...

Holden was certainly onto a Good Thing with its new sixes!

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But there was no easy answer when it came to Holden’s locally-built V8. Struggling against the lowered fuel octane, the base 5-litre V8 used a lowly 8.5:1 compression ratio but attempted to fight back with an upgrade exhaust and ‘big valve’ heads. The result? An abysmal 122kW from all eight cylinders... Fortunately, the unleaded 5-litre V8 produced decent torque (323Nm at 3200 rpm) which made it useable as a tow car. Later, the Permanent Red HDT Group A versions were tweaked to deliver 137kW and the HSV Walkinshaw (appearing with a twin-throttle EFI induction system) set a new benchmark with 180kW. Still pretty poor by today’s standards...

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Meanwhile, the majority of vehicles imported to Australia were only slightly impacted by unleaded fuel. Most other countries had already adopted unleaded fuel and manufacturers had revised their engines to suit. For example, Saab produced two versions of the 900 Turbo – the leaded version was sold in Australia through 1985 and from 1986 we received the unleaded version (which was already selling in large numbers in other counties). Invariably, power output was slightly reduced when stepping down to 91 RON unleaded.

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Fortunately, it wasn’t long before high-octane (95 RON+) unleaded became available and high-performance cars started producing the power output that we’re now accustomed to. Certainly, the availability of high-octane unleaded opened the doors to a variety of very quick cars.

‘90s to Present

Since the introduction of unleaded fuel in 1986 there have been no further drastic emission regulation changes imposed on local car manufacturers.

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However, from 1998 to 1999, ADR 37/01 was phased in for all new vehicles. ADR 37/01 requires a maximum of 2.1g/km carbon monoxide, 0.26g/km hydrocarbons and 0.63g/km oxides of nitrogen. These emission measurements are sampled in accordance to United Nations Economic Commission for Europe (UN ECE) test standards.

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In 2003 and 2004, Australian built cars were then required to meet ADR 97/00 which is identical to the widely recognised Euro 2 emission standards. Interestingly, Euro 2 carbon monoxide levels are more relaxed (2.2 versus 2.1g/km as previously) but the maximum allowable hydrocarbon and oxides of nitrogen levels are tightened to 0.28g/km and 0.22g/km. Note that oxides of nitrogen levels were slashed by around 60 percent.

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In 2005 and into 2006, it is required that Australian built cars comply with ADR 79/01 - which is equivalent to Euro 3 emission standards. Oddly, Euro 3 carbon monoxide levels are further relaxed (at 2.3g/km) but hydrocarbon levels are tightened to 0.2g/km and oxides of nitrogen are cut to a maximum of 0.15g/km. This is certainly an improvement over previous standards but it’s far from being a big leap forward.

The Future

Overseas, the latest emission standard (Euro 4) is enforced.

Euro 4 regulations allow just 1g/km carbon monoxide, 0.1g/km hydrocarbons and 0.08g/km oxides of nitrogen. Put simply, the maximum allowable emissions are cut by at least 50 percent compared to Australia ’s current Euro 3 standard!

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Note that many imported new cars arriving in Australia meet these stringent Euro 4 standards. The Holden Astra, Hyundai Sonata and Alfa 159 are examples.

Based on previous patterns, it seems likely that Euro 4 emission standards will be applied in Australia sometime after 2006 – it is widely rumoured around 2008. Unfortunately, there is still no motivation for manufacturers to build cars that produce low emissions together with low fuel consumption.

Ongoing Emissions Checks

As a car owner, it’s your responsibility to maintain a service schedule and avoid producing excessive tailpipe emissions.

In some parts of Australia , State/Territory governments operate a roadside emissions testing program where cars are typically pulled over at random. For example, the Queensland government operates a program called OVERT (On-Road Vehicle Emissions Random Testing).

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The OVERT program employs a team of specially trained Transport Inspectors that test the tailpipe emissions of your car using a four-gas analyser. The test is carried out with the engine at idle. Carbon monoxide and hydrocarbon levels are tested with different standards applying depending on the age of the car. For cars manufactured before 1986, the percentage volume of carbon monoxide should not exceed 4.5 percent and 400ppm hydrocarbons. Cars manufactured after 1986 should not exceed 2 percent carbon monoxide and 250ppm hydrocarbons. Following the test, each car is graded Good, Fair or Poor – the latter two results come with a recommendation to have the car serviced. Regardless of the test result, no legal action is taken.

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If you own a modified or smoky car you may be officially instructed to undertake the world-recognised I/M 240 emissions test. I/M 240 testing involves running the car on a dynamometer for a duration of 240 seconds. The engine is operated at only light to moderate load during the test and is driven the equivalent of 3.1 kilometres at an average speed of 47.3 km/h. Tailpipe emissions are monitored with a five-gas analyser and emissions are reported on the basis of mass per distance travelled. The maximum allowable level of emissions varies depending on model and year of car.

Note that I/M 240 is the emissions test required for modified vehicles in most parts of Australia but there are some States that require additional testing. We suggest contacting your local Department of Transport and Environmental Protection Agency for comprehensive details before making changes.

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