The New GM dexos Engine Oil Specification

For the 2011 model year, GM will introduce dexos1™ certified engine oil as a factory fill and service fill for many engines. The reason for the new engine oil specification is three-fold: meet environmental goals such as increasing fuel efficiency and reducing engine emissions, promote long engine life, and minimize the number of oil changes to help meet the goal of lowering the industry's overall dependence on crude oil.

 

 

dexos is a GM-developed engine oil specification that has been designed to:

·          Further improve fuel economy (to meet future Corporate Average Fuel Economy, CAFE, requirements) and fuel economy retention, which allows the oil to maintain its fuel economy benefits throughout the life of the oil

·          Provide a more robust formulation for added engine protection and aeration performance

·          Support GM's Engine Oil Life System (EOLS) and minimize use of engine oil

·          Ensure worldwide availability of high quality oil for factory and service fill needs

·          Reduce the duplication of requirements for a large number of internal GM engine oil specifications

 

TIP: The oil specified in prior model years remains acceptable for previous models; however, dexos1 is backward compatible for older vehicles.

 

If dexos1 is not available, acceptable substitute engine oil for 2011 models includes:

·          SAE-5W-30 viscosity grade oil displaying the API Starburst symbol for all 2011 model year vehicles with naturally-aspirated engines, except Corvette, Camaro SS (with LS3 engine) and CTS-V

·          SAE 5W-30 viscosity grade oil meeting the GM4718M specification (such as Mobil 1 Full Synthetic) for 2011 model year Corvette, Camaro SS (with LS3) engine, CTS-V and vehicles with turbocharged engines

 

dexos Classifications 

The dexos specification includes two classifications. 

GM will require dexos1 for global factory fill in spark ignited engines worldwide and service fill for gasoline engines worldwide, except in Europe. It will replace the GM6094M, GM4718M and GM-LL-A-025 specifications for most GM gasoline engines. 

dexos2 was introduced in Europe late last year for diesel engines as well as a service fill for gasoline engines. It replaces the GM-LL-B-025 and GM-LL-A-025 (in Europe) specifications.

 

GF-5 Standard 

In addition to GM dexos, a new International Lubricants Standardization and Approval Committee (ILSAC) standard, GF-5, will be introduced in October 2010. There will be a corresponding API category - SN Resource Conserving. The current GF-4 standard was put in place in 2004. The GF-5 standard will use a new fuel economy test, Sequence VID, which provides a statistically significant increase in fuel economy versus the Sequence VIB that was used for GF-4. 

It's expected that all dexos1 approved oils will meet GF-5. However, not all GF-5 engine oils will necessarily meet the dexos1 specification.

Like dexos, the new ILSAC GF-5 standard will call for more sophisticated additives. The API will begin licensing marketers (the first license is expected October 2010) to produce and distribute GF-5 certified products, which are expected to include SAE 0W-20, 0W-30, 5W-20, 5W-30 and 10W-30 oils.

 

Fuel Economy 

Since CAFE standards were first introduced in 1974, the fuel economy of cars has more than doubled, while the fuel economy of light trucks has increased by more than 50%. Proposed CAFE standards call for a continuation of increased fuel economy in new cars and trucks. To meet these future requirements, all aspects of vehicle operation are being looked at more critically than ever before. 

New technology being introduced in GM vehicles designed to address vehicle efficiency and fuel economy include direct injection, cam phasing, turbo-charging and Active Fuel Management. The demands of these technologies on engine oil also are taken into consideration when determining new oil specifications. Active Fuel Management, for example, can help to achieve improved fuel economy, however, alternately starting and stopping cylinders puts a lot of stress on engine oil.

Another industry trend for meeting tough fuel economy mandates has been a shift toward lower viscosity oils. Testing has shown that thinner 0W-20 oil can provide as much as a 4% improvement in fuel economy than 15W-40 oil. 

dexos1 will eventually be offered in several viscosity grades in accordance with engine needs: SAE 0W-20, 5W-20, 0W-30 and 5W-30. dexos 2 may be available in SAE 5W-30, 0W-40 and 5W-40, depending on engine needs.

 

TIP: Using the right viscosity grade oil is critical for proper engine performance. Always check the appropriate vehicle owner manual for the proper viscosity grade for the vehicle being serviced.

 

Increased Service Intervals 

To help reduce the consumption of oil while maintaining proper engine protection, many GM vehicles equipped with the GM EOLS have a maximum oil change interval that is much longer than what was considered a normal interval just a few years ago. 

If all GM vehicle owners would follow the EOLS intervals in their vehicles as intended, GM estimates that more than 100 million gallons of oil could be saved annually. 

The second generation EOLS will rely on significantly more engine operating information than the current system, which, combined with dexos approved oil, could allow a significant extension of the maximum oil change interval. dexos specifications call for improved oil robustness to support extended drain intervals over a vehicle's lifetime.

 

dexos1 Availability 

dexos1 will be available through the GM Goodwrench Oil Program in addition to a full line of products, including conventional GF-5 oil, Mobil 1 Full Synthetic and others. It will be available in 55 gallon drums (which can be pumped into bulk tanks) as well as packaged quarts. In Canada, dexos1 will be available through the ACDelco Oil Program in 205L drums and packaged 1 liters. 

More information about availability and part numbers will be coming soon.

 

 

- Thanks to Matt Snider and Eric Johnson