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Auto Repair Service

Why Oil Changes Extend the Life of your Engine

Written by: Max Revelli

Engine Oil – A Modern Marvel

Engine oil is the most critical fluid in your vehicle. Not only resisting the relentless friction of your engine’s internal components, but also minimizing wear from day-to-day usage, modern engine oil represents the pinnacle of material science and chemical engineering. Read on to learn why oil change services are so important!

The Importance of Lubrication

Early engine oil was basic, but sufficient for the rudimentary needs of early internal combustion engines (ICE). At its core, an ICE creates rotational energy by making use of the explosive force of a mixture of air and fuel burning. This force acts upon one or many pistons, forcing them to move downwards. This force is harnessed into rotational energy by the crankshaft, to which the pistons attach and rotate with. To hold up to the immense stresses of this action, internal engine components must be made from strong metals. Think of a squeaky door hinge, spray some oil on it and the squeak is gone. Metals do not slide against each other very easily. Without a lubricant, two metal objects rapidly moving against each other would quickly wear out. We expect our vehicles’ engines to last longer than one drive, and thus rely heavily on the properties of engine oil. 

The advent of the internal combustion engine marked a massive leap forward in engineering and manufacturing. Engineers understood the importance of a lubricant to not only increase the lifespan of an engine, but also its efficiency. Think of trying to slide two iron cooking pans against each other. It would be rather difficult, however add a little cooking oil, and the pans become slippery, and easy to move against each other. While cooking oil is not suitable for use in combustion engines, the principle is the same. Reduce friction, and therefore increase efficiency and minimize wear. 

Advancing Oil Technology

The earliest combustion engines used refined animal fats as oil. However, it was quickly understood that the engines were far too demanding for the lubricating properties of animal fats and would wear out rapidly. The next leap forward saw the use of crude oil as an engine oil, but this still lacked the properties to deliver reliability and efficiency. Despite what one may think, crude oil that comes out of the ground shares very little in common with today’s engine oils. Engineers discovered that crude oil could be refined to increase its effectiveness as an engine oil. Refined crude oil marks the start of the development of modern engine oil. Using refined crude oil, otherwise called conventional oil, cars of the early 1900’s all the way up through the 1970’s could operate reliably and with relative efficiency. Oil changes were required more frequently during this time at every 3000 miles.

As time progressed, and engines became more advanced, the demands placed upon an engine’s oil increased. Faster rotating speeds, tighter mechanical tolerances, and stricter efficiency requirements saw conventional oil fail to ensure safe smooth operation in modern engines. Conventional oil could not hold up to the demands of modern engines, and would need to be changed frequently, or else risk a loss of protection from engine wear. Synthetic motor oil was developed to increase the service life and improve on the performance and chemical properties of conventional oil. 

Common Oil Misconceptions

The term “Synthetic” or “Full Synthetic” oil is somewhat deceptive as most synthetic motor oils on the market are still derived from crude oil. Modern motor oils can be broken down into two main parts, the base stock, and the additive package. The base stock determines whether an oil can be marketed as conventional, synthetic blend, or synthetic. Base stocks make up much of the volume of the oil and can be classified into 5 groups. Groups 1-3 are petroleum based. Group 4 is Polyalphaolefin (PAO) based, which is a fully synthesized molecule that improves upon the properties of petroleum-based products. Group 5 consists of all other fully synthetic base stocks, but namely ester-based stocks. The confusion arises with what US law allows to be marketed as synthetic or full synthetic oil. For comparison, German marketing and advertising laws are much stricter and oils labelled as “vollsynthetisch” or fully synthetic must consist of majority group 4 or 5 base stock. Most oils sold in the US as full synthetic still use a group 3 base stock. While a group 3 base stock significantly improves on the properties of groups 1 and 2, it is still derived from petroleum products. 

Oil Standards and Certifications

You may be asking, what does this mean for me? In truth, not much. This is because nowadays oils are tested rigorously to ensure that they will meet the demands of the engine it is being used in, regardless of base stock. There are regulating bodies, for example, the American Petroleum Institute (API) or Society of American Engineers (SAE) that set test benchmarks that engine oils must meet to gain certification to be used in combustion engines. On top of this most vehicle manufactures set their own set of guidelines for oil manufacturers to meet to sell a motor oil suitable for use in their engine. All current major European manufacturer light passenger car oil specifications require at least a group 3 base oil, since inferior bases cannot hold up to the demands of modern engines. While all of this may seem confusing, as long as you, or your trusted repair facility, is diligent about ensuring the proper oil is used for each application, and you are having oil changes done at specified intervals, you can expect your engine to perform as designed. You can trust Precision Motorworks to only use the highest quality oils in your vehicle. We stock and carefully select the correct engine oil for your specific vehicle that has the proper manufacturer approvals. 

The Importance of Choosing the Proper Oil Specification

Choosing the correct engine oil for your vehicle is extremely important. While old engines were not very picky about the type of oil used, modern engines are. In modern engines, oil not only serves its basic purpose of lubrication and wear protection, but is also used in advanced mechanical control systems. Many modern engines make use of variable valve timing to increase efficiency and power. Standard engines that operate with non-variable valve timing are bound to intaking air, and exhausting combustion biproducts at set times. Variable valve timing allows the vehicles computer to choose, which has a drastic increase in engine efficiency and power. The majority of these systems operate using oil pressure which is controlled by electronically actuated solenoids that regulate oil pressure to valve timing adjusters. The engine computer expects the oil to act reliably and predictably in these systems. Using the incorrect viscosity or specification of oil will cause these systems to malfunction and may lead to costly repairs. 

There are many other systems used in modern vehicles that require specialized engine oil. Namely the use of direct fuel injection (DI). Direct fuel injection has been common since the early 2000s but is now in use in nearly every passenger car gasoline engine. This is because injecting the fuel directly into the combustion chamber vastly increases efficiency. When manufacturers started widely implementing DI, it was quickly discovered that the oil used caused a major problem. Calcium, which is added to engine oil as a cleaner, or detergent would cause something called low speed pre ignition (LSPI) commonly referred to as “knock”. This is caused when the air fuel mixture ignites before it is supposed to and can cause major engine damage if not corrected. Upon this discovery, the API designed a new set of test criteria dubbed “SP” and later revised to “SN”.This mandates lower levels of calcium and alternative detergents be used and signifies that the engine oil is suitable for use in turbocharged direct injection vehicle and will not cause LSPI.High calcium oils are still widely used in non-DI vehicles with no ill effects; however, this demonstrates the care that must be taken when selecting the correct oil to use for your vehicle. 

The Importance of Proper Oil Change Invervals

While you can trust that all oils certified by the manufacturer of your vehicle will function properly with your engine, the one thing manufacturers cannot control is the vehicles owner carrying out regular servicing. Regular oil changes are imperative in maintaining a healthy and reliable engine. Manufactures set guidelines for how often a vehicle should be serviced and the engine oil changed. However, this should be considered a bare minimum requirement. Many European vehicle manufactures’ top priority is not overall vehicle longevity. A question many people ask when buying a new car is “how much will this vehicle cost to own”. For this reason,manufacturers stretch recommended service intervals to the maximum theoretical capability of the engine oil and filter. This allows them to advertise a very low cost of maintenance. In practice, however, this does your engine no favors. Manufacturers want to sell new cars; they don’t make much money on vehicles as they age. Their incentive is not to recommend what is best for you and your car, but instead the bare minimum to keep your vehicle running beyond the warranty period, and through the average ownership length of the first owner. After the vehicle trades hands, it is much less likely that the second owner will return to the selling dealership for service and repairs due to high cost, and thus no money will be made. 

This is why at Precision Motorworks, we recommend a 5,000-mile or 6-month oil change interval. The longevity of engine oil can be tested in several ways. The most common and easy way to ensure peace of mind is to stick to regular service intervals, however a brief visual inspection of your oil dipstick can tell you a lot. Dark or dirty oil signifies you are overdue for a change. Ideally you don’t want to let the oil get to this point as it starts to lose its effectiveness. This can be scientifically tested with a few tests. Similar to what the SAE develops to test new oil, the American Society for Testing and Materials (ASTM) develops procedures to test the capabilities of new oil and the health and degradation of used oil. A flashpoint test (ASTM D92) is commonly used to test fuel dilution in oil. Fuel dilution happens when not all fuel is burned, and some makes its way into the engine oil. It is a normal occurrence that happens over the service life of engine oil, and oils are designed to be capable of operating correctly even with some fuel dilution. However,when the oil is not changed frequently, fuel dilution reaches a level that prevents the oil from adequately protecting your engine and may cause excessive wear and shorten the service life. 

While there are dozens of ATSM tests, another popular method to determine whether an oil is still effective is a TBN test(ASTM D2896 and D4739) TBN stands for total base number, which simply put indicates an oils ability to effectively neutralize acidic contamination. Contamination is another common occurrence that modern oil is equipped to handle. Like fuel dilution though, oil can only handle so much contamination. A TBN test, while not perfect, offers strong insight into the remaining effectiveness of an engine oil. These tests require highly specialized equipment and can only be performed at a laboratory. This is why we recommend 5,000-mile or 6-month oil changes, the average person will not perform used oil testing, and would rather change their oil frequently for peace of mind. 

Oil is the most critical operating fluid in your vehicle, as we frequently say, “Oil is cheap, engines are expensive”. Staying on top of your oil changes ensures peace of mind and is the easiest way to keep your engine internals happy. Give us a call, text, or email if you have any questions or would like to schedule an oil change service. We service the following European automotive brands: Audi, BMW, MINI, Land Rover, Jaguar, Porsche, Mercedes, Volvo, and Volkswagen.

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