Let' talk about motor oil in general for a minute. Motor oil is the life blood of an engine. It consists of two basic components, the base stock and the additives. The base stock makes up the majority of the volume of the oil and is responsible for lubricating the moving parts of the engine and removing heat. It also seals the piston rings.
Base stocks can be made from, (1) crude petroleum that goes through a refining process, (2)chemicals that are synthesized in a laboratory setting, or (3) a combination of the two. A petroleum base stock is composed of a number of different sizes and shapes of long chain carbon molecules that are sensitive to heat and tend to boil away at relatively low temperatures. Over time this leads to sludge and varnish buildup and changes in the oil's viscosity. In synthetic base stocks the molecules are uniform in shape and size rendering them much more resistant to the effects of the heat inherent in internal combustion engines. Synthetic oil base stocks retain their molecular structure and physical properties (such as viscosity) much longer and because of the molecular uniformity have a lower coefficient of friction and are much better at transferring heat away from moving parts.
The chemicals that make up the additives in motor oil are put there to provide specific properties not inherent in the base stocks themselves. These include anti-wear, anti-foam, protection from corrosion, neutralization of acid, maintenance of viscosity and detergency or cleaning properties. The quality and quantity of additives varies greatly depending on the required specifications. Some oils only provide additive levels that comply with minimum industry standards while others offer very high quality additives in quantities that meet high performance requirements.
As internal combustion engines and drive-trains become more sophisticated the lubricants they use must meet higher and higher standards. At this time about approximately10% of the lubricants used today are synthetic. We will start seeing this percentage increasing rapidly as more and more vehicle and equipment manufacturers begin recommending synthetics in their new vehicles and oil and filter change intervals continue to increase.
Additives Make the Base Stock Better.
Oil additives are basically chemicals that provide increased anti-wear, anti-foam, corrosion protection, neutralization of acid, viscosity maintenance, detergency (the cleaning properties of the oil) and dispercency. Let's take these one at a time.
* Most of an oil's function is to prevent friction and wear between moving parts in an engine or drive-train component. The additives bond to the metal surfaces and form a protective film between moving parts that are at the most risk of wear during start-up and before the oil warms up and circulates completely. Although this protective film doesn't entirely eliminate metal to metal contact it minimizes the effect of that contact.
* Silicone is one of the common chemicals added to oil in small amounts to keep it from foaming when it is circulating through the equipment. Foaming is undesirable because the air bubbles can create a frothy mass that has little ability to lubricate or transfer heat, which are the two most important functions of the oil.
* When oil is heated over time it begins to produce acidic gases that combine with condensation in the crankcase. If left unchecked this results in corrosion and rust of the metal components. It is important that oil has properties that inhibit acid formation. Synthetic base stocks are generally more resistant to acid formation than petroleum base stocks and oxidation inhibitors work to inhibit the impact of oxidation.
*The most important property of an oil, viscosity, refers to the oil's resistance to flow. An oil's viscosity will change when it changes temperature. It becomes thinner when hot and thicker when cold. To maintain its maximum lubricating ability oil must remain viscous enough when hot to offer a protective layer between moving parts and must be able to flow at cold temperatures to lubricate moving parts upon engine start-up. Viscosity improvers are chemical polymers that decrease the viscosity fluctuations of oil when exposed to fluctuating temperatures. Since synthetic base stocks are inherently "viscosity stable" they require less viscosity improver additives than petroleum based oils.
*Detergents are added to motor oil to keep combustion by-products from building up on pistons, rings, valves and cylinder walls in the form of varnish and sludge deposits. Without detergent additives, varnish and sludge can effect oil circulation and clog the oil channels running throughout the engine, resulting in inadequate lubrication to critical engine components.
*Dispersant additives keep any combustion by-products that do form and find their way into the engine oil suspended in the oil as it circulates. They are then picked up by the oil filter and eliminated.
*It is important that oil is compatible with the various gasket and seal materials used in an engine. Additives can be added that will enable the seals to swell slightly and remain pliable rather than becoming hard, then cracking and causing leaks.
Why is all of this important? Because, with oil you get what you pay for. The more expensive oils, in general, are composed of higher quality base stocks and additives. Paying a little extra for a premium lubricant will save money and time down the road due to decreased breakdowns and improved fuel economy.
Is the 3000 Mile Oil Change Dead?
The old standard 3000 mile oil change, promoted for years by most motor oil companies and especially quick lube businesses, is going by the wayside. Vehicle manufacturers have recently begun recommending oil change intervals exceeding 3,000 miles. Most are now recommending intervals of 5000 miles or more. Ford Motor Company began recommending 7500 mile oil change intervals in 2007.
In the December 2006 issue of Consumer Reports drivers were encouraged to follow the longer oil change recommendations of vehicle manufacturers saying, "Although oil companies and quick-lube shops like to promote this idea (that engine oil should be changed every 3,000 miles) it's usually not necessary. Go by the recommended oil change schedule in your vehicle owner's manual. Most vehicles driven under normal conditions can go 7500 miles or more between changes. Some models now come with a monitoring system that alerts the driver when the oil needs changing. The California Environmental Protection Agency and its Integrated Waste Management Board (CIWMB) launched a public information program and website designed to "bust the 3000-mile myth" and encourage drivers to reduce used oil volume by following the longer oil drain recommendations of vehicle manufacturers.
In addition to the environmental benefits associated with less waste oil, extended drain intervals with synthetic oil saves consumers money. Assuming a consumer drives 15,000 miles in a year and does 5 oil changes at $30 per change, the 3000 mile oil change interval will cost $150.00 over the course of a year. Changing to synthetic oil that will last 7500 miles will cost approximately $120.00 and an oil change with oil that will last 15,000 miles will cost approximately $100.00, saving $50 per year. Additional savings occur from an expected increase in gas mileage of 3% to 5% due to the ability of the synthetic oil to reduce friction within the engine.
The question then becomes; where do you find oil that will last 15,000 miles? There is only one oil company that manufactures a completely synthetic oil and guarantees it 15,000 miles or more and has been doing so for 35 years. The name of the company is AMSOIL, Inc. You can view a comparison of AMSOIL Synthetic Oil with other leading brands of oil on our website and judge for yourself whether synthetic oil is for you and your vehicles or equipment.
Extended oil drain intervals are here to stay and synthetic oil is the only type of oil that will hold up for that long. If you are going to use synthetics, doing your homework will allow you to receive the best value available.
