Oil Changes

Oil Changes

Motor oil or engine oil is oilthat is used for lubricationof various internal combustion engines. The main function is to lubricate moving parts. Oil also cleans, inhibits corrosion, improves sealing, and cools the engineby carrying heataway from moving parts.

Oil Usage

Motor oil is a lubricantused in internal combustion engines. These include motor or road vehicles such as cars and motorcycles, and heavier vehicles such as buses and commercial vehicles. In engines, there are parts which move against each other causing frictionwhich wastes otherwise useful power by converting the energy to heat. Contact between moving surfaces also wearsaway those parts, which could lead to lower efficiency and degradation of the engine. This increases fuel consumption, decreases power output and can, in extreme cases lead to engine failure. Lubricating oil creates a separating film between surfaces of adjacent moving parts to minimize direct contact between them, decreasing heat caused by friction and reducing wear, thus protecting the engine. In use, motor oil transfers heat through convectionas it flows through the engine by means of air flow over the surface of the oil pan, an oil cooler and through the build up of oil gases evacuated by the Positive Crankcase Ventilation(PCV) system.

Oil Grades

The Society of Automotive Engineers(SAE) has established a numerical code system for grading motor oils according to their viscosity characteristics. SAE viscosity gradings include the following, from low to high viscosity: 0, 5, 10, 15, 20, 25, 30, 40, 50 or 60. The numbers 0, 5, 10, 15 and 25 are suffixed with the letter W, designating their “winter” (not “weight”) or cold-start viscosity, at lower temperature. The number 20 comes with or without a W, depending on whether it is being used to denote a cold or hot viscosity grade.

Other Oil Additives

In addition to the viscosity index improvers, motor oil manufacturers often include other additives such as detergentsand dispersants to help keep the engine clean by minimizing sludge buildup, corrosion inhibitors, and alkaline additives to neutralize acidic oxidation products of the oil. Most commercial oils have a minimal amount of zinc dialkyldithiophosphateas an anti-wear additive to protect contacting metal surfaces with zincand other compounds in case of metal to metal contact. The quantity of zinc  dialkyldithiophosphate is limited to minimize adverse effect on catalytic converters. Another aspect for after-treatment devices is the deposition of oil ash, which increases the exhaust back pressure and reduces fuel economy over time.

Synthetic Oil and Synthetic Oil Blends

Synthetic lubricants were first synthesized, or man-made, in significant quantities as replacements for mineral lubricants (and fuels) by German scientists in the late 1930s and early 1940s because of their lack of sufficient quantities of crude for their (primarily military) needs. A significant factor in its gain in popularity was the ability of synthetic-based lubricants to remain fluid in the sub-zero temperatures of the Eastern front in wintertime, temperatures which caused petroleum-based lubricants to solidify owing to their higher wax content. The use of synthetic lubricants widened through the 1950s and 1960s owing to a property at the other end of the temperature spectrum, the ability to lubricate aviation engines at temperatures that caused mineral-based lubricants to break down. In the mid 1970s, synthetic motor oils were formulated and commercially applied for the first time in automotive applications. The same SAE system for designating motor oil viscosityalso applies to synthetic oil.

Tests show that fully synthetic oil is superior in extreme service conditions to conventional oil, and may perform better for longer under standard conditions. But in the vast majority of vehicle applications, mineral oil based lubricants, fortified with additives and with the benefit of over a century of development, continue to be the predominant lubricant for most internal combustion engine applications.

Bio-based Oils

Bio-based oils existed prior to the development of petroleum-based oils in the 19th Century. They have become the subject of renewed interest with the advent of bio-fuels and the push for green products. The development of canola-based motor oils began in 1996 in order to pursue environmentally friendly products. Purdue University has funded a project to develop and test such oils. Test results indicate satisfactory performance from the oils tested.



Oil being drained from a car

In engines, there is inevitably some exposure of the oil to products of internal combustion, and microscopic coke particles from black sootaccumulate in the oil during operation. Also the rubbing of metal engine parts inevitably produces some microscopic metallic particles from the wearing of the surfaces. Such particles could circulate in the oil and grind against the part surfaces causing wear. The oil filterremoves many of the particles and sludge, but eventually the oil filter can become clogged, if used for extremely long periods. The motor oil and especially the additives also undergo thermal and mechanical degradation. For these reasons, the oil and the oil filter need to be periodically replaced. While there is a full industry surrounding regular oil changes and maintenance, an oil change is a fairly simple operation that most car owners can do themselves.

Some vehicle manufacturers may specify which SAE viscosity grade of oil should be used, but different viscosity motor oil may perform better based on the operating environment. Many manufacturers have varying requirements and have designations for motor oil they require to be used.

Motor oil changes are based on the time in service or the distance that the vehicle has traveled. Actual operating conditions and engine hours of operation are more precise indicators of when to change motor oil. Also important is the quality of the oil used, especially with synthetics (synthetics are more stable than conventional oils). Some manufacturers address this (for example, BMW and VW with their respective long-life standards), while others do not. The viscosity can be adjusted for the ambient temperature change, thicker for summer heat and thinner for the winter cold. Lower viscosity oils are used in many newer vehicles.

Re-refined Motor Oil

The oil in a motor oil product does not break down or burn as it is used in an engine—it simply gets contaminated with particles and chemicals that make it a less effective lubricant. Re-refining cleans the contaminants and used additives out of the dirty oil. From there, this clean “base stock” is blended with some virgin base stock and a new additives package to make a finished lubricant product that can be just as effective as lubricants made with all virgin oil. The US Environmental Protection Agency defines re-refined products as containing at least 25% re-refined base stock, but other standards are significantly higher. The California State public contract code define a re-refined motor oil as one that contains at least 70% re-refined base stock


No matter what type of oil your vehicle uses, Bay Area Automotive Services has the capability to provide your vehicle with the optimum oil you desire. Stop by, call us, or email us to find out what types of oil changes we offer.

Remember that maintenance is key. 

Getting your oil changed regularly will help keep your vehicle running better and lasting longer.

Please note that there is a minimum $59.17 (plus ss & tx) vehicle diagnosis charge for vehicles that do not complete repairs same day with our facility.

Thank you for your understanding.

Reference from YouFixCars.com Retrieved fromhttp://en.wikipedia.org/wiki/Oil_change