new passenger car motor oil specification
Dexos1™ Gen 3 is a global engine oil specification introduced by General Motors (GM). The new specification is designed to meet performance needs of GM vehicles and includes a more recent version of the stochastic pre-ignition (SPI) test, fuel economy test, and upgraded performance limits for deposit and sludge tests. There is some overlap with dexos1 Gen 2 when compared to the latest industry standard, ILSAC GF-6, but dexos1 Gen 3 still has enhanced oxidation, turbocharger protection and engine cleanliness. GM has set a mandatory transition date of September 1, 2022 to meet its dexos1 Gen 3 specification.
Oronite received its first GM dexos1™ Gen 3 approval from General Motors after having conducted extensive testing on existing and new formulations that deliver on the company’s latest passenger car motor oil (PCMO) technology.
OEM relationships are critical for additive companies to meet the needs of today’s equipment and anticipate future needs.
Oronite’s current technology OLOA® 55600 and 55516 series deliver GM dexos1 Gen3 flexible solutions and have proven performance in critical dexos1 Gen 3 tests. New technology products are modified to retain the robust GF-6 & dexos1 Gen 2 performance of current technologies and delivers <0.80% sulfated ash dexos1 Gen 3 solutions. With a reliable supply, simplified logistics and solutions easily adapted to your product offerings, we can help meet your ever-changing oil performance needs.
Oronite is well-positioned to be the dexos1 Gen 3 provider of choice with our innovative technology solutions cover both dexos1 Gen 3 and ILSAC GF-6/API SP, API SP RC. We offer simplified logistics, optimized treat rates, and flexible base oil, viscosity modifier and PPD coverage with PARATONE® chemistry. Our products deliver superior performance over dexos1 Gen 2 and GF-6, as well as provide protection for hybrid vehicles and turbocharged GDI engines.
Originally, GM announced the first license date for dexos1 Gen 3 as May 1, 2021 with dexos1 Gen 2 claims expected to be obsolete after May 1, 2022. However, in April 2020, the GM dexos1™ team announced a delay in the release of the specification due to the uncertainty of the COVID-19 pandemic. In early August 2020, GM announced the start of dexos1 Gen 3 testing as September 1, 2020; first license date September 1, 2021; and that dexos1 Gen 2 claims are expected to be obsolete after September 1, 2022.
Oronite’s new dexos1 Gen 3 products will have different treat rates based on your requirements. Fully cascadable additive technology can simplify your logistics and help reduce costs. One flexible additive means only one tank to supply all your products. Within the bottom and top of the cascade, there are many options for performance differentiation.
Stochastic Pre-Ignition (SPI) is also known as Low Speed Pre-Ignition (LSPI). It is an abnormal combustion event where the fuel-air mixture ignites before intended, similar to “knocking.” The main difference from knocking is pressure. SPI or LSPI events can result in pressure spikes up to 130 times atmospheric pressure, which is about 2.5 times the normal pressure in the engine. This can cause a catastrophic mechanical failure, but it can be controlled by your motor oil. Many OEMs are developing in-house LSPI tests for their own engine designs. GM's dexos1 specification now includes a GM stochastic pre-ignition test (GMSPI). This test is similar to the Ford LSPI test used in GF-6, albeit at different operating conditions.
New and upcoming engine oil specifications include low speed pre-ignition (LSPI) prevention. ILSAC GF-6 includes a Ford engine test to discriminate oils based on LSPI event prevention (reduction). Thus, all oils that make ILSAC GF-6 claims are formulated to address LSPI. The new GMSPI test will incorporate transient engine testing (aggressive throttle and engine speed changes) and is expected to be more severe over the previous generation test.
Engine oil formulations have an impact on the frequency of LSPI events based on initial work performed by Oronite and several other industry experts. Various studies have taken place to investigate the impacts of fuel, lubricant, hardware, and other factors, on LSPI. Certain lubricant components have been found to promote LSPI while others are neutral or can actually suppress LSPI. For example, Calcium, Iron, Sodium metals have shown to promote LSPI while Molybdenum and zinc dialkyldithiophosphates (ZnDTP) tend to suppress LSPI.
Many of these compounds are included in the engine oil formulations to provide performance in various areas. They can’t simply be removed without affecting other areas of performance. In order to formulate for LSPI, a rebalance of compounds is needed to provide needed performance in all areas, not just LSPI performance.
Dexos1 Gen 3 will be backward compatible with previous generation dexos1. GM has outlined a timeline for final “sale” of dexos1 Gen 2 targeted to be Sept 1, 2022 (one year after first license for dexos1 Gen 3).
We do not expect diverging technology pathways here. Dexos1 Gen 3 includes a number of the ILSAC GF-6 required sequence tests and is viewed by GM as more of a “tightening” of the Gen 2 specification rather than a “step change.”
Group II and II+ base oils are certainly allowed in dexos1 Gen 3 formulations, but GM will allow limited to no read-across for formulations that contain greater than 30 percent group II/II+. This typically applies to 5W formulations and could possibly apply to 0W formulations with a GIII+ or PAO trim fluid.
Our technology meets dexos1 Gen 3 requirements of less than 0.9wt% sulfated ash. We have also developed technology to meet lower ash levels of less than 0.80% sulfated ash which is required in some regions such as China.