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News   August 12, 2010   by CARS Magazine

Oil for all: Many choices for crankcase connoisserus

Oil, not gasoline, is the lifeblood of any auto engine. Without oil, the lifespan of an engine would be very s...


Oil, not gasoline, is the lifeblood of any auto engine. Without oil, the lifespan of an engine would be very short indeed. Every technician knows that changing the motor oil regularly is the best insurance for any vehicle.

Many years ago there was a very limited choice in oils. Whatever the technician found at-hand was poured into the engine and in worked fine. These days, it is not so simple. There are a plethora of choices: synthetic oils, high-mileage oils, semi-synthetic oils and mineral oils that can confuse the average consumer.

The easiest way to know what oil should go into a vehicle’s engine is to look at the owner’s manual.

Jorgen Mueller, the owner of Kipling Car and Truck Service in Toronto, said, “Most cars now prescribe what oils they should have in them. Most newer Volkswagens and other European cars specify synthetic oil and the grade that is required,” he said. “Some manuals will specify which brand to use, like Mobile 1.”

“During a vehicle’s warranty period, one should stick to OEM-recommended oil change intervals, even if using extended performance motor oil,” said Raihan Khan, field marketing advisor PVL, Imperial Oil lubricants & Specialties. “Many vehicles are now equipped with oil change reminder lights and these typically tell the consumer when to change the oil. Once the vehicle is no longer under OEM warranty, the owner of the vehicle may choose to extend oil drain intervals.”

There are a lot of misconceptions about synthetic oils. “Synthetic oil is still derived from crude oil, just like mineral oil. The major difference is that it is more refined,” said Dan Dotson, lab manager at Valvoline’s headquarters in Lexington, Kentucky. Like in the distillation of alcohol, the more you refine crude the better the product, according to Dotson. “The molecules of synthetics oil are more uniform and smaller, and we are able to manipulate these molecules more effectively to achieve what we want,” he said. “Synthetic oils won’t break down as quickly and will retain its viscosity longer.”

Imperial Oil’s Khan said, “In very high temperatures and under stressful driving conditions, synthetics also hold their viscosity, break down less and therefore can keep an engine cleaner. Many of the synthetic oils also have more uniform molecules, which provide better lubrication.”

As cars are getting smaller, engines are shrinking but becoming more powerful and efficient. This is one of the reasons auto manufacturers are insisting synthetic oils be used. “In order to meet the demands of these engines, oil formulators have to incorporate more and more synthetic base stock. In general, synthetic base stocks offer excellent protection and oil flow at wide temperature extremes. On top of that, the use of synthetic base stocks allows the oil formulators more freedom to optimize all of the other components in the engine oil recipe and “build” a very robust product that has outstanding protection and performance,” said Debbie Van Schalkwyk, Global Pennzoil brand manager. “Pennzoil Platinum motor oil with (its cleansing agents) helps keep engines clean even under temperature extremes, helps prevent sludge and other damaging deposits, helps clean up existing sludge in your engine, helps protect emission systems and controls high temperature oxidation and deposits.”

Although many synthetic oils claim a longer life, you should still change oil at the recommended intervals. “You should not extend the change intervals, said Valvoline’s Dotson. “Yes the synthetic oil is better and stable. It filters the dirt and the dirt in the engine is still there. You will still have dirty oil. It will be better dirty oil. You should follow the manufacturer’s recommendations for oil changes.”

Mark Sach-Anderson, the shop manager at Dr. H Honda in Toronto, said, “certainly you can go longer intervals between oil changes by using synthetic, but there is not an engine rebuilder out there that would agree with that statement. You should always change your oil at regular intervals, 5,000 kilometres or every three months.” Dotson adds, “The one thing most mechanics will tell you is that if you want to keep your car longer you should change your oil often.”

When to use mineral-based motor oils

Switching the engines oil from mineral to synthetic oils is a question that many consumers pose to themselves and to the people who maintain their vehicles. “I would recommend mineral oils for older cars,” said Sach-Anderson. “Synthetic oil is more likely to cause oil leaks on older cars. Mineral oils are a lot better than they used to be. When you look at some of the discount store brands they are garbage. You should always look for a good quality mineral oil. What I would suggest is going with a high-mileage oil and changing the oil more frequently.”

He would switch to synthetics if there was a lot of customised work done on the engine and the engine was under severe stress.

What constitutes severe stress on an engine is a matter of debate, according to Dotson. Dusty conditions and a lot of stop-and-go driving all fall under extreme duress for an engine he said. “When it comes to extreme conditions, like very high temperatures, extreme loading on the engine, like when you are towing or you have dusty conditions, you are putting a lot of stress on the engine. This is when you should consider switching to synthetic oil.”

People are keeping their cars longer and putting many more kilometers on the odometer. In the 1960s and 70s, it would be rare to have a car with 160,000 kilometers (100,000 miles). These days it is very common to see cars driving on the road with well over 200,000 kilometers sowing on the dashboard. For older engines with high mileages, the lubrication industry has come up with specially formulated oil aptly called high-mileage oil.

“After a time the seals will start to break down dry up and crack and start to shrink, said Dotson. “What we have done is formulated an oil, Valvoline Max Life and Max Life Full Synthetic, that conditions the seals and brings them back to life. So this will help the engine to perform better.”

“High mileage engine oils are technically different from other engine oils,” said Van Schalkwyk from Pennzoil. “High mileage oils are typically slightly thicker in viscosity – but still within the SAE grade listed on the bottle. Years ago, when an engine had worn rings and started to consume oil, consumers may have tried thick SAE 20W-50 oils to help slow down the oil consumption and help seal the worn rings.

“With today’s extended warranties, high mileage oils offer a thicker version of the manufacturers recommended viscosity grade. High mileage engine oils are typically formulated to help resist oil burn off by formulating the oil to resist evaporation – or volatility – better. Higher mileage oils may include a seal conditioning additive properly balanced into the recipe, to help revitalize and rejuvenate certain plastic and rubber seals that may have started to age over the years.”