Reportaje: Es momento para un cambio de aceite al motor de mi vehículo


By Anna Kulow

As car owners, we secretly dread the moment when the odometer reading matches the number on the sticker in the upper corner of our windshield. Every 5,000 miles or so, we must take an our busy lives to get an oil change. Most of us trust the mechanic performing the task to choose the best oil for our vehicule. 

But is that always the best choice for our planet?


According to the California Department of Health Services, over 40 percent of pullution in American waterways is from used motor oil. Rivers and streams transport nearly 500 million gallons of used motor oil into our oceans, making in the greatest source of petroleum pollution in the marine enviroment.

However, motor oil is essential to making a car run smoothly because it prevents the moving metal parts of the engine from actually coming in contact with each other. Instead, they glide along a thin coating of oil, preventing wear and tear. Oil also circulates through the engine, cooling certain parts, such as your transmission. Finally, oil acts to trap particulates and other impurities to keep your engine clean.

The most important characteristic of motor oil is its viscosity, wich is its resistence to flow. Oil has a higher viscosity than, say, water or alcohol. Moving an object through oil is a lot more difficult than moving the same object through water. Therefore, the vast majority of motor oils are made from a heavy, thick petroleum-based stock delivered from crude oil with additives to improve certain properties. When motor oil leaks from vehicles or is improperly disposed of, it is not only the petroleum oil being washed into our waterways, but also host of chemicals additives.

One of the critical additives in motor oil are called viscosity index improvers (VIIs). When an oil type has two numbers, such as 10W-30, it means VIIs have been added to ensure the oil remains liquid at a wider range of temperatures. VIIs are made up of large molecules called polymers. Due to the large size, they tend to persist in the enviroment and float in water surfaces. Although VIIs are generally considered to have low toxicity, few studies have examined their impact on marine wildlife.

Other chimicals added to improve the performance of motor oil include ante-wear and extreme pressure additives, corrosion inhibitors, detergents and dispersants to minimize sludge build-up, and alkaline additives to neutralize acidic oxidation products of the oil. When used oil is improperly disposed or burned, these chemicals are also transported into waterways. The anti-wear agent ZDDP is well-known to be toxic to aquatic organisms and is not readily biodegradable, meaning it is more likely to make its way into our waterways and oceans.

What are the alternatives to petroleum-based motor oil and are they any better for protecting ocean life?

You have probably encountered one of them: Syntethic oils. Synthetic oils were developed in Germany during cool war due to the lack of crude availability. There are two types of synthetic motor oil sold today with the base stock being either polyalphaolefin (PAO) or ester. PAO is a large-molecule syntethic hydrocarbon. While it is shown to persist in the enviroment, it is no readily taken up by organisms due its low bioavailablity. Esters are readily biodegradable in the enviroment, but 100 percent ester oil has been associated with increased levels of particulate polyaromatic hydrocarbon (PAH) in vehicule emissions, wich can then precipitate from the atmosphere into water bodies and cause mutagenic and carcinogenic effects in aquatic organisms.


  Photo by Robert Couse-Baker via Flickr Creative Commons (bit.ly/22yOVIV)
  Photo by Robert Couse-Baker via Flickr Creative Commons (bit.ly/22yOVIV)

However, syntethic oils offer several advantages to conventional oils. They have a higher viscosity index and, generally, have higher performance capabilities than conventional motor oil. Therefore, they require lower amounts of VIIs and others additives than petroleum-based oils, meaning fewer chemicals making there way into the enviroment. Synthetics also provide better engine wear protection, produce less sludge (keeping your engine cleaner), and can last up to 25,000 miles before needed to be changed. 

So why isn´t everyone using synthetics? 

The major downside is cost. An oil change using synthetic motor oil can cost up three times as much as a conventional oil change. However, the longer oil change intervals coupled with the long-term benefits to your vehicle and the enviroment, easily make up for the additional cost.

Recently, lubricant research has been largely focused on bio-based oils derived from plants and other renewable materials. Biosynthetic Technologies, a California-based company is manufacturing a high performance ester-based stock derived from fatty acids found in plant oil. Ther product is renewable, non-toxic, biodegradable, and does not bioaccumulate in organisms. While early-stage plant-derived synthetics had performance problems, new formulations are providing performance benefits matchng or exceeding  conventional oils, meaning substantially fewer toxic additives need to be mix in.

Next time you go for an oil change, consider the impact your choice in motor oil has on the health of our oceans. Ask your mechanic about newer bio-based oils. Although you might not think your choice makes a difference, consider that the average vehicle loses three gallons of used motor oil to the enviroment. According to the U.S. Enviromental Protection Agency (EPA),  just one gallon of motor oil can contaminate one million gallons of fresh water. Your choices make a difference in improving the health of our waterways. Our planet´s odometer is telling us it is time for an oil change.


Anna Kulow is a freelance writer based in Solana Beach, Ca. 

This article is part of the Silent Oil Spills public awareness campaign.


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