GM dexos® 1

Just as the automotive industry released and licensed the ILSAC GF-6 specification, GM has also released its next generation dexos® 1 specification, dexos® 1 Gen 3, that is slated to be first licensable in September 2021. The aim for this upgrade is to address the motor oils’ challenge to address new engine hardware, mainly smaller, higher power density engines equipped with new technologies. 

While the GM dexos® 1 Gen 3 specification includes most of the ILSAC GF-6 engine tests, most of these tests will have significantly higher limits than ILSAC GF-6. In addition to the GF-6 tests, dexos® 1 Gen 3 has its own specified engine tests to evaluate low-speed pre-ignition mitigation, fuel efficiency, oxidation and turbocharger deposit performance and wear protection. 

GM dexos® 1 Gen 3 Tests

GM dexos® 1 Gen 3 is bringing in a mix of ILSAC GF-6 and legacy GM tests with more stringent limits as well as new GM tests to meet the needs of modern, high-tech gasoline engines in GM vehicles.

Below is a breakdown of what each test accomplishes for dexos® 1 Gen 3:

Test Performance Description
GMA Aeration Oil foaming resistance during normal engine operation
GMLSPI Low-speed, pre-ignition LSPI protection & mitigation for T/GDI vehicles
GMTC Turbo coking Deposit formation protection on the turbocharger
GMOD Oxidation & deposit Oil performance at high operating temperatures
GMOEE Fuel economy Fuel economy performance using a Chevy Silverado chassis dyno
MTM Wear Protection against wear using a bench test
Sequence IVB Cam wear Wear prevention on the engine cam load
Sequence VH Sludge & varnish Deposit or “sludge & varnish” build-up prevention
Sequence VIE Fuel economy Fuel economy & fuel economy retention as the oil ages
Sequence VIII Corrosion Rust prevention on critical engine components
Sequence IX Low-speed, pre-ignition LSPI protection & mitigation for T/GDI vehicles
Sequence X Chain wear Chain wear protection from soot particles in GDI engines


GM dexos® 1 Gen 3 Relative Performance Comparison

The performance chart is not a literal translation of a performance specification and should not be used as a replacement for evaluating engine oil performance in accordance with the relevant vehicle manufacturer’s requirements.

NOTE: the relative performance of the dexos® 1 Gen 3 wear specification is ranked slightly lower than dexos® 1 Gen 2 since GM removed an engine test (RNT) and replaced it with a bench test (MTM). Generally, an engine test is a better method of evaluating performance. The specification does still utilize the Sequence IVB wear test, which is also part of the API and ILSAC specifications. The sludge-handling performance comparison is a similar situation where GM removed a sludge handling engine test (M271 EVO) and replaced it with the Sequence VH (API/ILSAC), a final formulation test with more stringent limits than those of ILSAC GF-6.

The specification ensures that all dexos® 1 Gen 3 oils will still be very strong on wear protection and sludge handling and reflects the emphasis that has been put on cleanliness, fuel economy and LSPI protection for GM vehicles.