The Development of JASO GLV-1 Next Generation Low Viscosity Automotive Gasoline Engine Oils Specification 2020-01-1426

It is well understood that using lower viscosity engine oils can greatly improve fuel economy [1, 2, 3, 4]. However, it has been impossible to evaluate ultra-low viscosity engine oils (SAE 0W-12 and below) utilizing existing fuel economy test methods. As such, there is no specification for ultra-low viscosity gasoline engine oils [5]. We therefore developed firing and motored fuel economy test methods for ultra-low viscosity oils using engines from Japanese automakers [6, 7, 8]. This was done under the auspices of the JASO Next Generation Engine Oil Task Force (“TF” below), which consists mainly of Japanese automakers and entities working in the petroleum industry. Moreover, the TF used these test methods to develop the JASO GLV-1 specification for next-generation ultra-low viscosity automotive gasoline engine oils such as SAE 0W-8 and 0W-12. In developing the JASO GLV-1 specification, Japanese fuel economy tests and the ILSAC engine tests for evaluating engine reliability were used. The fuel-saving performance and engine protection performance of four reference oils (two of them SAE 0W-8, the other two SAE 0W-16) and three demonstration oils (SAE 0W-8) were evaluated. The results indicated that these test methods could be used to evaluate SAE 0W-8 oils. The JASO GLV-1 specification values were then considered. In the fuel economy tests, the demonstration oils GE308 and GE408 showed superior fuel-saving performance compared to a general purpose fuel-efficient SAE 0W-16 engine oil (GE216) formulated without a molybdenum friction modifier. In the engine reliability tests, only GE308 satisfied the ILSAC GF-5 requirements. These results confirmed that ultra-low viscosity oils such as SAE 0W-8 can provide high fuel-saving performance and sufficient engine protection. In the JASO GLV-1 specification, the requirement for fuel economy was set based on fuel economy tests performed using engines from Japanese automakers, and the requirements for engine protection were set based on the ILSAC GF-5 tests. We have also confirmed that GE308 fully meets the specification, which became effective in April 2019.