Kiwi you might find this interesting...particularly if you're, like me, old enough to remember the glory days of guilt free V8s
Oil companies convinced us that unleaded petrol is safer for our health and environment than leaded petrol.
By their failure to disclose all the facts, we have been seriously conned!
Compiled by Catherine Simons, B.Sc.
The very terms "leaded" and "unleaded" are misleading. They give the impression that "leaded" petrol is contaminated with something nasty, namely lead, while "unleaded" is somehow pristine, pure. Whilst it is true that "leaded" petrol contains lead, and lead is not a nice substance to have spewing out of the exhaust pipes of millions of cars, the truth is that unleaded petrol has even nastier properties. Let's start at the beginning.
When internal combustion engines were first developed for the automobile, they ran on a substance known as "motor spirit". By today's standards, motor spirit was an exceptionally "clean" fuel; properly burnt in an efficient engine, the main exhaust products were water vapour, carbon dioxide and some trace carbonic elements and particles. There were two main problems with motor spirit. First and foremost, it was a highly refined product which cost the oil companies far more to produce than what they wanted to spend, or what they thought they could charge if the automobile was really to take off in a big way. Secondly, the original combustion engines ran at very low compression ratios compared to today. As the vehicle manufacturers strove to produce ever faster, more powerful engines, they gradually raised the compression ratios, as this is one of the easiest ways of gaining more power from any given-sized power plant.
So, for a period, these two problems developed side by side until they eventually collided with the development of the V-8 engine. On the one hand, fuels were becoming less and less refined, and therefore more contaminated with products that adversely affected engine efficiency. On the other hand, power plants were being developed which employed ever higher compression ratios and required ever more exacting performance from the fuel used. With the advent of the high-compression engine, a point was reached where cars would not run satisfactorily on the product being supplied by the oil companies. An engine under load would develop a condition known as "pinging", where the fuel mixture would explode due to compression before the right time, causing rough running, stalling going up hills, and so on.
There was only a shortlist of answers. Vehicle manufacturers could go back to designing low-compression engines, the oil companies could go back to producing a highly refined product, or something would have to be found that could be added to stop the fuel pre-igniting. The first choice was unacceptable to the manufacturers. They had long since embarked on a marketing strategy that demanded ever bigger, ever more powerful power plants every year. Nobody was prepared to take the risk of producing a less-efficient, less powerful engine than the one offered the year before. The second choice was unacceptable to the oil companies. They had perfected the technique of producing a fuel with a minimum of refining, that could still be burned in engines, at such a low price and in such quantities that they were well on their way to becoming the richest, most powerful companies on Earth. They had no intention of greatly increasing the cost of their product, thereby turning many people off the "advantages" and "economy" of owning their very own car.
The third choice was the only acceptable one. All that was needed was to find some product, something that could be obtained cheaply, that could be added to petrol to reduce its tendency to "ping" under compression. Common lead was found to have all the right properties, and so "leaded" petrol was born.
By the late 'sixties, supplies of high-grade, low-sulphur, low-nitrate oil were becoming scarce enough to command premium prices. This type of oil was favoured by the petroleum producers, since removing these contaminants to an acceptable level is difficult and costly. The companies were refining increasing amounts of the cheaper, high-sulphur, high-nitrate oil, but using the same old processes. This in turn led to ever higher levels of sulphur dioxide and nitrogen oxide in vehicle emissions, and people were starting to complain-if not about the environmental effect, then at least about the smell. The smog banks over the bigger American and Australian cities during this period were not, as most people believe, the result of so many more cars on the road, although this, of course, was a contributing factor. The main cause was the vastly increased levels of sulphur/nitrogen oxides in the vehicle emissions because of the higher levels of contamination in the fuels themselves. The oil companies were once again faced with the dilemma of cleaning up their product or finding another solution that did not affect their profits. The chemical theories and practices of catalytic conversion had been known for many years.
It had always been known to the oil companies that they could use these processes to further refine their petroleum products. This, however, would have meant major upgradings of their refineries. Far better if they could get somebody else to foot the bill. Even better if they could get somebody to meet the cost of total responsibility for all the oxides.
In the 'fifties, a lot of work was done trying to utilise the CO2 from such fixtures as coal and oil electric power stations to increase plant growth. These efforts failed because of the harmful effects of the concentrations of other pollutants in the exhausts. These were principally the same sulphur/nitrogen oxides. At the time of these experiments, it was discovered that passing the exhaust gases through a filter of platinum caused a catalytic conversion of the oxides to other products which could then be prevented from escaping into the greenhouses used for food production. The problem at the time was that it was not economically feasible to do this: platinum converters are very expensive things, and they do eventually wear out and require replacing. There was an added problem that the eventual by-products were in many cases even more harmful than the original oxides. This information then remained unused for some decades.
THE BIG CON
Eventually the blankets of sulphur and nitrogen oxides, better known as smog, grew so thick and so unbearable that "public opinion" caused America's legislators to start looking for answers. Obviously the place to start was with the oil companies. The oil companies announced quite loudly, and mostly erroneously, that the problem was "so many cars".
There were only two solutions, they said: either limit the number of cars, or put something into the cars to "change" and limit the emissions. Was such a thing possible, asked the legislators? Certainly, replied the oil companies. Let us tell you about "catalytic converters" which can be fitted to the exhaust system of every car.
The legislators, although they toyed with the concept, were not about to try and seriously interfere with people's rights to drive motor cars. Such action was perceived as electoral suicide, especially when there was the alternative "magic bullet" solution of converters available. Neither were they about to listen to all the "extremists" who were trying to tell them that the problem was in the type of oil being refined in the first place, and the only long-term solution was to get the oil companies to clean up their act. Such people contribute very little to election campaigns; the petrol chemical giants contribute millions. There was only one problem left for the oil companies. Unfortunately, while platinum doesn't react to any great degree with the products of burnt petrol, it reacts very readily with lead-so readily, in fact, that burning a single tankful of "leaded" petrol in a car with a catalytic converter will render the converter useless. (This is the reason it is illegal to put "leaded" petrol in the fuel tank of a car designed to run on the "unleaded" variety.)
Trouble was, the oil companies couldn't simply stop putting lead in petrol, because the original reason for its presence-to stop "pinging"-still existed. There were available alternative additives that could be used, but these all had the disadvantage that, untreated, they produced emissions far more deadly than even the lead. On the plus side, however, these emissions could be filtered out by catalytic converters. What was needed, then, was a campaign to convince people that "leaded" petrol was a grave danger to the environment, and that the only solution was to cease using it, replace it with the "unleaded" variety, and then run the emissions through a catalytic converter. Such a campaign would ensure that legislation was passed forcing the fitting of catalytic converters, which would overcome the original problem for the oil companies-the increased levels of sulphur and nitrates in their fuel. You see, the campaign never had anything to do with lead: it was simply a matter of convincing people to use a fuel that wouldn't wreck the converters, so that the petroleum companies didn't have to spend any more money refining the oil and could get away with selling a dirtier product, forcing the motorist to bear both the responsibility and the cost of trying to clean up the air.
Anybody who doubts it was the quality of the petrol rather than the number of cars which caused the massive increase in smog in the period in question, need only look to actual figures. While it is true that the number of cars in use was increasing, the rate of increase was fairly steady. At the height of the "smog wars", however, the levels of emissions were increasing at nearly four times the rate of growth of car ownership. On top of that, this was the period where petrol was starting to get more expensive, and "economical" engines were becoming the order of the day. That is, although both car ownership and petrol consumption were on the increase, rate of ownership far outstripped rate of increase of consumption.