Dexos1 Gen 3 Tests Available Sept. 1


General Motors’ proprietary tests required for its Dexos1 Gen 3 passenger car engine oil licensing will be available beginning Sept. 1, said GM Engineering Manager Nathan Siebert during a webinar last week. Gen 3 will replace Dexos1 Gen 2, which debuted in 2017.

The automaker is in discussions with laboratories to ensure there will be enough testing capacity for all blenders seeking the original equipment manufacturer’s seal of approval, Siebert assured attendees of the Aug. 5 webinar, which was organized by the Independent Lubricant Manufacturers Association. He also said that GM has implemented changes to its licensing process that will improve turnaround time for approvals.

The final performance specifications and test limits for Gen 3 were submitted for GM’s internal review, which typically takes a few months, Siebert continued. Those details are likely to be published at the end of the year.

In December, GM said the new spec will include all of the engine tests for the ILSAC GF-6 passenger car engine oil specification, with the exception of Sequence IIIH, which will be replaced by the GM oxidation and deposit test. This test will have stricter limits than the Sequence IIIH, as will GM’s requirements for the Sequence VH sludge test. Many Dexos1 Gen 2 test methods will be carried over, including a low-speed pre-ignition test and a test for turbocharger deposits, both at tighter limits.

Other limits, including Noack volatility and sulfated ash, will also be tightened.

First available use for the Dexos1 Gen 3 mark will be Sept. 1, 2021. In keeping with how the OEM handled the transition to Dexos1 Gen 2, marketers will have 1 year to sell off their Gen 2 products before they must be pulled from the shelves, he said.

Siebert wouldn’t comment on future viscosity grades for Dexos gasoline engine oils. “We will make the viscosity grade selections that will provide the best engine performance to our customers,” he demurred.

He did point out, however, that the OEM developed its own diesel engine oil specification – DexosD – because the desired SAE 0W-20 viscosity grade wasn’t available under API CK-4 or FA-4 heavy-duty engine oil service categories. GM recommends DexosD SAE 0W-20 oils for its 2020 model year full-size trucks with 3-liter engines.

Siebert also warned attendees that GM is on the lookout for marketers that violate their Dexos contracts. Forty-eight percent of labels and a quarter of products fail GM audits, according to the OEM. Major sources of failures for labels include logo sizing and image clarity, particularly in relation to background colors that were changed from what was originally submitted to GM for approval.

The majority of product failures involve base stock substitutions without prior approval form GM. “The remainder and more serious issues have been around introduction of materials such as esters that are not part of the original formulations, manufacturing errors regarding bottling of non-Dexos materials in Dexos bottles, and not blending in proper ratios of base stocks to additive packages,” Siebert said.

“This has led GM to revoke licenses of some ILMA members to protect our customers and ensure that they have the highest quality products on the market.”