Originally Posted by General Motors Corp.
DETROIT (April 22, 2003) - With the explosion in information technology especially available through the Internet, it is easy to find advice on almost any subject. Vehicle maintenance is one subject that gets significant attention, and determining when to change engine oil is commonly discussed.
Use of the GM Oil Life System will often double or even triple the oil change interval for a typical vehicle when compared to the 3000-mile oil change.
The typical recommendation made is to change every 3000 miles, which is a conservative approach that is typically accepted as the industry standard by those who sell oil changes for a living. Their common rationale is that frequent oil changes are "cheap insurance" for extending engine life. $20 to $30 spent for an oil change might be considered cheap, but this can amount to hundreds of dollars spent over the life of the vehicle with no benefit realized. To gain the best value from the cost of an oil change, the mileage between changes should be maximized as long as there is no adverse effect to the engine. Not only does this approach save money, but it also helps to protect the environment due to the reduced consumption and disposal of used oil.
In keeping with its commitment to sustainable mobility, General Motors now installs its award-winning Oil Life System on nearly all new North American vehicles.
Giving consumers an accurate and reliable way to monitor engine oil life will help reduce America's appetite for oil, protect the environment and save consumers money while still ensuring that engines are properly maintained. The GM Oil Life System provides a win-win solution to the difficult issue of engine oil changes. This is just one of many advanced technologies that GM uses to help reduce pollution and conserve natural resources
After many years of research, GM has learned how to maximize oil drain intervals while also maintaining engine life. Researchers learned that oil degrades in a predictable fashion and that monitoring a few engine-operating conditions allows oil life to be determined quite accurately. Specifically, the engine computer monitors engine speed to count combustion events while also estimating oil temperature based other engine operating conditions. From here, the computer is able to determine the rate of oil deterioration and notifies when to change oil. This software based GM Oil Life System is part of the same computer that also helps to control engine functions and is now available on most GM vehicles. With this system, the guesswork of knowing when to change oil is removed.
Engine oil lasts longest at operating temperatures of about 200 degrees Fahrenheit.
As the graph at right demonstrates, the mileage between oil changes is very dependent on the temperature of the engine.
Oil life can be maximized if its temperature is maintained around 200 degrees F. Highway driving exemplifies this type of operating condition. Conversely, when an engine is started cold, contaminants from the engine combustion such as water and fuel can enter the oil. If the engine is not allowed to warm up, contamination can build up in the oil, which results in reduced mileage between oil changes. Finally, trailer towing in a warm climate can increase engine oil temperature, which will also reduce oil life.
Most vehicles are typically operated under a variety of conditions. As a result, use of the GM Oil Life System will often double or even triple the oil change interval for a typical vehicle when compared to the 3000-mile oil change. The GM Oil life system keeps track of the various operating conditions of the vehicle and adjusts the mileage between oil changes respectively. With this, there is no longer any need to guess at when to change oil. Consumers can be confident that they aren't damaging the engine by running bad oil, nor will they be wasting time, money and resources by changing oil that has a lot of useful life remaining.
Since 1995, GM has produced more than 18 million vehicles with the Oil Life System. Together, these vehicles had the potential saving 70 million gallons of oil to date if the system was used as intended. That is more than six times the amount of oil spilled by the Exxon Valdez. Likewise, it is estimated that consumers could have saved more than $1 billion in service costs by avoiding unnecessary oil changes. The social benefit of the GM Oil Life System was recognized when GM received a first-ever Environmental Excellence in Transportation (E2T) Award from the Society of Automotive Engineers in 2001.
It is recognized that used engine oil is a significant environmental problem if not properly managed. The GM Oil Life System helps to reduce oil change frequency, thereby helping to preserve valuable petroleum resources and reducing the amount of used oil that requires oil disposal. It is important to remember that GM dealerships follow environmentally sound practices when disposing of used oil. By having your vehicle serviced at a GM Goodwrench dealership, any adverse environmental impact can be minimized.
Although GM uses this system in nearly all cars that it produces, there are still some vehicles without the system. In these vehicles, oil change intervals are still based on a two-schedule system. Drivers making lots of short trips around town or towing trailers should change their oil every 3,000 miles while those making relatively long cruising trips should be on a 7,500-mile interval. Since most drivers do some combination of both styles of driving, the guidelines are far from precise. In fact, because these guidelines are intentionally conservative, a lot of oil is being drained before its useful life has ended.
NOTE: The Oil Life System will be available on all light-duty North American GM cars except for some models of Buick Park Avenue and Le Sabre, Pontiac Bonneville and Sunfire/Sunbird, Chevrolet Geo, Tracker, Cavalier and Malibu, S10/Sonoma trucks, and Astro/Safari Vans
