Comment by Liam Mitchell
The uses of unleaded petrol (ULP) and catalytic converters in post-1986 cars raise many questions. Kirk, McCabe, Hoyer and Bain (Write on, GLW #286) ask why oil companies keep information on the health effects of ULP suppressed. The answer is simple — they don't want to pay the costs of decreasing pollution, preferring to increase the toxic emissions from vehicles.
Catalytic converters have been fitted by law to all petrol vehicles since 1986. The reason given was that they provide further combustion of toxic gases — sulphur and nitrous oxides and raw fuel — that are either produced by burning petrol or incomplete combustion (which is true), giving clean air out the exhaust (in theory, carbon dioxide, water and oxygen).
However, the use of catalytic converters introduces many problems. A converter will work only when it is hot, often allowing toxic gases through when a car's engine is still cold, or during extended idling. This includes chemical additives called aromatics — volatile organic compounds which include benzene, toluene (methyl-benzene), dimethylbenzene, xylene and mesitylene (1,3,5 triethyl-benzene) — which replace the lubricant and anti-detonation properties of lead.
Converters are needed because the fuel itself is not clean enough to provide complete combustion. The companies are pushing the costs of cleaning up exhaust emissions onto the consumer. Catalytic converters do not last the life of a car and become less effective with time, adding further expense for the motorist.
The quality of the fuel is critical for combustion. Late model cars with fuel injection are prone to problems from dirty fuel blocking filters and injectors (which is very common), causing inefficient and incomplete combustion and a build-up of toxic gases in the exhaust.
Thus in the chain of high technology in late model vehicles to make them more fuel efficient and less polluting (and sell more cars), fuel has become a weak link.
Inefficient combustion is extremely damaging to the engine — particularly the catalytic converter. A blocked fuel injector would dribble a small amount of petrol into the combustion chamber, resulting in a lean mixture and subsequent misfire and incomplete burning of the petrol.
As the engine uses more fuel to compensate for the lack of power, more and more unburned fuel is dumped into the exhaust, creating a meltdown effect in the converter, eventually destroying it and even blocking the exhaust.
Dirt in fuel is caused not so much by oil companies, but by the underground tanks at service stations. However, the fuel from the oil companies is often made from low grade oil, which results in contaminants.
Lead itself in petrol was never the problem it was made out to be. Studies have shown that the amount of lead in petrol has no correlation with lead levels in the atmosphere or human blood, and indeed the lead particles are hardened in the combustion process, making it not easily absorbable through the lungs or stomach and heavier than air, collecting in dust at the side of the road. Lead was removed purely because it damages the catalyst coating in a converter.
Government and industry campaigns have tried to convince us to use ULP in pre-1986 cars, despite the damaging effect this can have on some engines. This would also have the effect of increasing the benzene level of exhaust gases, produced from the burning of these aromatics.
If this is not bad enough, the oil companies have been reducing the lead content in leaded petrol (e.g. Shell's half lead) and increasing the aromatic content to the point of being on par with ULP! The result is that there are now more toxic gases pumped out of these vehicles than before.
Oil companies should be made to divulge all their scientific data for audit and be made to pay for cleaning up their product and exhaust emissions from the wealth they have made from selling dirty fuel and poisoning our air.
Catalytic conversion of fuel should be done before it reaches the bowser; the oil companies would not do this voluntarily due to the increased cost in setting up this process.
Alternatives to aromatics in fuel should also be explored. Some South American countries use ethanol-based fuels successfully. We could use the sugar industry as a source for ethanol or methanol as substitutes. Again the problem is that oil companies do not own the sugar industry, so there is no money in it.
What is needed is the political will to force these companies to change the way they produce fuel so that the costs would not be pushed onto the consumers. Part of this is to explain the harmful effects of both leaded and unleaded petrol and the use of catalytic converters in cars to clean up exhausts.
But change will come only when the environment movement takes up the reasons behind capitalism's changes to our fuel.