Without any public announcement, the federal government has quietly bowed to oil company pressure and given them another eight years before they must produce the same low-sulphur petrol already mandated and used in major international markets such as Europe, Japan, China, and India.

High sulphur levels in petrol create a contaminant coating on a car's underbody catalytic converter, greatly reducing its effectiveness to treat tailpipe emissions.

Australia's 91-octane standard fuel is allowed to have sulphur levels as high as 150 parts per million. The world standard in markets such as China, Europe, India and Japan is 10ppm.

Australia's standard grade fuel also has a low octane level by international standards. Many European cars imported here now can't use it, and increasingly fewer vehicles sold here will tolerate it.

National fuel quality standards have been under review for more than five years with successive federal ministers avoiding the decision to mandate the high quality petrol needed by car makers to achieve the cleanest European emission levels.

Any raising of national emission standards was also predicted to cost consumers more, although this has been hotly disputed by some international experts.

In December 2016 a federal government draft assessment on improving the efficiency of new light vehicles claimed the cost of new cars could go up by between $131 and $776 by 2020 due to new engine technology required to meet stricter emissions standards.

In its submission, Australia's oil refining industry said the future viability of the local refiners would be endangered by an accelerated timetable - before 2027 - to cut the sulphur content in our standard grade fuel.

The industry said it would have to invest "approximately $979 million which may threaten the economic viability of the remaining refineries in Australia".

Just four oil refineries remain in Australia: Mobil in Melbourne, Viva/Shell in Geelong, BP Kwinana near Perth, and Caltex in Brisbane.

Without a local refining capability, national fuel security would quickly emerge as a major political issue for the federal government.

Motoring organisations say that the government not acting on mandating lower sulphur levels is good news because it keeps 91 fuel - our cheapest, lowest grade and highest sulphur petrol - in the market for another eight years.

However, stalling the shift to improved fuel quality shuts Australia away from the improved emissions standards which world-class 10ppm sulphur fuel delivers.

Although car importers had a strong case to argue at a time when international focus was on cleaner emissions, the industry's advocacy group mounted a limp and ultimately unsuccessful campaign.

For consumers, the change in the car market will not be immediately apparent.

What must happen however, is that vehicle choices in Australia will diminish.

Many small, super-efficient petrol cars being produced for Europe won't be offered here because they simply cannot tolerate our poor-quality, high-sulphur fuel.

The current car market already has a great divide between those vehicles that can run on low grade 91 RON fuel and those cars at the grave risk of engine damage if owners try doing so.

This divide between standard grade petrol cars and expensive premium fuel cars will become a chasm in the years ahead.

A small number of new cars will run on the cheapest fuel and produce the highest emissions. However, more expensive new cars with sophisticated, clean engine technology will need premium fuel which costs between 10 to 15 cents more per litre.

If this complication doesn't rush us all toward buying electric cars, then nothing will.