Saturday, December 1, 2007


Good motoring
Change engine oil, filter frequently
H. Kishie Singh

Maintenance-free’ is a common word in the auto world today. It refers to the battery, the car itself and also the engine oil. All of this is partially true. A maintenance-free battery does need maintenance. The car needs an overall inspection periodically, and the oil—be it engine, gear box or differential—does need special care. Whereas the gear-box and differential oils will last up to 50,000 km, the engine oil, which is the lifeline of the car, needs extra care.

Oils today can be petroleum-based, para-synthetic or fully synthetic. The main job of oils is to lubricate, reduce friction and wear and tear on moving parts. It also helps in sealing microscopic irregularities in between the cylinder walls and rings to maintain compression.

The oil also has a detergent action. It collects all the dirt and other unwanted particles and deposits them in the filter.

Keeping all this in mind, if you want a long life for your engine, change engine oil and filter frequently.

There is a term ‘severe service’. It means frequent stops and long idling periods. It also includes long idling periods at red lights. Delhi traffic is an excellent example. It includes trips of 10 km or less when the air temperature is below 10?C. This will happen in Chandigarh in the next five months. Sustained high-speed driving in hot weather is also ‘severe service’. This will happen from April to August when the air temperatures can soar to almost 50?C on your way to Jaipur. Also, driving in dusty conditions, we have this all over north India, and this is also an example of ‘severe service’.

As a principle car owners should use a good petroleum-based engine oil and change the oil and filter every 5,000 km, irrespective of what manufacturers say. It promises the long life of your engine and ensures peace of mind.

Contrary to popular belief, smaller engines—800 cc up to 1600 cc—which are four-cylinder, run faster (engine rpm) and hotter on leaner fuel mixtures (to give better fuel average) than a bigger V-8 engine. Surveys have shown that the increased rpm of a four-cylinder engine means it would have nearly twice the movement of its engine parts as compared to a V-8 engine if both ran at the same speed. Smaller engines plus higher rpm means more heat and shorter engine life.

The same applies to turbo-charged and diesel engines. The diesel in our country is not of the best quality. As a result of the much higher compression ratio of a diesel engine, the deposits of soot, carbon, condensed moisture and possibly microscopic metal particles, diesel engines require a special oil. The designation CD on the oil is what is best for your car, SUV or RV. Incidentally, never change oil without changing the oil filter. A lot of people tell me: "I change my oil every 5,000 km and filter every 10,000 km." Doesn’t make sense. The oil filter is bound to be partially clogged. It won’t work efficiently and it will also recirculate the muck from the old oil with the fresh oil.

Did you know that the rotor on the turbo-charger on your car runs at 100,000 rpm? So if you come home, do not switch off the engine immediately. Wait at least 30-40 seconds. This allows the oil to circulate through the inter cooler and cool down. Now you know what the inter cooler does.

There is no argument that the fully synthetic oils last longer due to lack of acid build-up and better viscosity retention at below zero temperatures. They leave the engine cleaner. Due to lesser friction it improves the fuel consumption, leaves cleaner spark plugs and results in less smoke emissions.

But here is the other side of the coin. A good petroleum oil like Castrol GTX or Elf Sporty costs about Rs 180 per litre and the drain period will be 5,000 km. Mobil One costs Rs 900 per litre and the drain period will be 20,000 km. However, you may be obliged to change the filter every 5,000 km. A filter will not last 20,000 km, and every time you change the filter you’ll have to add 250 ml of oil, which is worth Rs 175, and that is the price of one litre of Castrol GTX.

Think about it. The choice is yours.

Happy motoring.






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