Used motor oil and Asian urban smog pollution

MANILA — In many major Asian towns and cities in China, India, the Philippines, Thailand, and other countries, a lot of the public transport and hauling conveyances are built from vehicles with surplus dilapidated engines. In trying to save money the wrong way, many of the owners improperly filter used motor oil without the right equipment and mix it with some new oil to return it back to their already poorly maintained engines. At times they may not even bother to mix it in with new oil and use all the old oil.

The outcome? A disastrous combination that results in high rates of vehicle air pollution in many Asian cities like Bangkok, Shanghai and Manila. The improperly filtered oil contributes to what mechanics call “blow by,” wherein an engine starts to burn motor oil (instead of just gasoline or diesel). The sight of a vehicle burning oil with their black plumes of thick smoke is a common sight.

Vehicle owners in developed countries know that if they put dirty motor oil in their engines, the contaminants in the oil such as small metal particles will act like sandpaper to increase engine wear. After some time, the engine will start burning oil, thus causing increased motor oil and fuel needs, as well as issues with smog enforcers. The engine itself will eventually be damaged, requiring an expensive overhaul, or worse, a replacement.

There is a way to properly reuse motor oil, by filtering and refining it, but the proper equipment needs to be available to do this. In developed countries these systems exist and are commonly used.

Used motor oil itself is both an environment and health hazard. The used oil from a single oil change can contaminate millions of gallons of clean water. It is also harmful to humans, as it contains nasty contaminants like toxic heavy metals and other byproducts of the internal combustion process. When the engine starts to burn oil, the smog itself contains benzene, polycyclic aromatic hydrocarbons, particulate matter, and other chemicals harmful to the skin and lungs.

For many countries, the main weapon against vehicular smog is the annual smog test prior to vehicle registration and spot smog checks on the roads. Unfortunately, this is a reactive way of dealing with the problem of air pollution that does not address the root causes. The enforcers in several countries are poorly paid, and in many cases are easily bribed.

What Asian governments need to consider is to find a way to deal with the root causes of vehicular air pollution, and not just focus on apprehension after the fact. Aside from encouraging migration of vehicle fleets to newer, cleaner low/zero emission vehicles and encouraging petrol companies to clean up their fuel, the problem of improper motor oil reuse also needs to be addressed. This can be done by making the price of new oil attractive and putting the right facilities in place to handle used oil.

Originally published at

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