.jpg?h=329&w=1170&la=en&hash=F94F4CBF1148D4C5DFB039CDF9A10F87 "JASO T903:2023 Motorcycle Specification Is Here")
The JASO T903:2023 specification for four-stroke motorcycle oils has been released. Here we discuss the key drivers and purpose of the revision, what changes are being made and what this means to key stakeholders.
The Japanese Automobile Standards Organization (JASO) small engine specifications continue to be adopted globally by the industry as key performance standards for both 2-stroke and 4-stroke applications.
For 4-stroke applications, JASO introduced the T903 specification in 1998 as a global standard; ensuring approved motorcycle oils simultaneously meet minimum performance requirements for the engine, clutch and gears. Since that time regular revisions to the specification have followed, the last in 2016, to ensure the standards remain relevant to the latest motorcycle hardware requirements.
This new release is the fifth revision to the JASO T903 specification.
Market Drivers and Purpose of the JASO T903 Revision
The JASO T903:2023 Revision
Formally named “Motorcycles – Four-Stroke cycle gasoline engine oils (JASO T903:2023)”, the fifth revision to the T903 specification includes changes to the following:
1) Engine Oil Quality Standards
To meet the latest hardware needs and the resulting increased severity in oil operating conditions, the American Petroleum Institute (API) SG and SH categories have been removed from the new JASO specification to upgrade the minimum level of crankcase performance. This is to ensure adequate protection against build-up of engine sludge, oxidation or wear in the latest hardware applications. This means the minimum crankcase performance level for new registered formulations will be API-SJ, in line with current API standards. Also in line with the latest API oil classifications, the JASO specification has been updated at the upper end of the performance range to include API SN Plus as well as API SP. These categories provide further performance benefits including emissions system compatibility, oxidative stability and deposit control for the most severe modern hardware applications.
At the same time, crankcase performance standards from ACEA or ILSAC have been removed from the category lists, given there have been very few submissions from oil marketers in previous years based on these core specifications.
2) Changes in the Phosphorus Content and Evaporation Loss
To enhance durability of the motorcycle three-way exhaust catalyst, the phosphorus upper limit has been reduced from 0.12mass% to 0.10mass%. The minimum level of 0.08mass% remains unchanged in order to not compromise wear protection and gear pitting performance. The reduced limit of evaporation loss from 20 max to 15 max ensures improved performance against oil consumption.
3) Clutch Friction Characteristic Test
The friction plate material used in the SAE#2 test, which measures friction performance of the clutch, is being upgraded to ensure it is representative of the latest friction material being commonly used in modern hardware. There is also a change in the reference oils used in the test due to availability and to ensure continuity of supply through the duration of this specification revision.
JASO T903:2023 Timing
- JASO T903:2023 specification was released on May 8th 2023
- Oil marketers able to commence first licensing from October 1st 2023
- For JASO T903:2016 new applications can be made until September 30th 2023
- Current valid T903:2016 on file data will be expired by April 30th 2028
Our View
The trend toward use of lighter viscosity oils for increased fuel efficiency reduces oil film strength and places increased stress on the additive anti-wear system. This has the potential to give rise to wear durability issues, however formulating to counter this is made more challenging by increased restrictions in phosphorus content. The need to deliver enhanced catalyst compatibility effectively limits the use of conventional anti-wear chemistry. This requires the use of novel anti-wear components and a different formulating approach to ensure a balanced approach to deliver the performance, efficiency, durability and catalyst compatibility required by the latest hardware.
For oil marketers, the first point of note is that any formulations registered under the T903:2011 version of the specification will soon expire and will need to be upgraded. Formulations registered under the T903:2016 version will be valid until 2028 meaning that there is no immediate need to upgrade existing registered formulations. Going forward, offering JASO T903:2023 approved motorcycle oils will ensure both current and future hardware oil performance requirements can be met as part of an effective and future-proofed product portfolio.
For more information on motorcycle oils, contact your Lubrizol representative.
.jpg?h=658&w=1170&la=en&hash=F051DD2E78BEB30AA9C87A6F3D2BB06D "The global motorcycle market is seeing a noticeable drive toward greater performance and increased efficiency.")
.jpg?h=658&w=1170&la=en&hash=2DEEF13172DE3CF243E21672AE444A02 "The Need for a Motorcycle Oil Performance Upgrade")
