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.
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.
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.
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!
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...
Meanwhile, the majority of vehicles imported to
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
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.
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.
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.
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.
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.
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
current Euro 3 standard!
Note that many imported new cars arriving in
these stringent Euro 4 standards. The Holden Astra, Hyundai Sonata and Alfa 159
Based on previous patterns, it seems likely that Euro 4 emission standards
will be applied in
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
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).
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
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