JASO M 364
Direct answer: JASO M 364 is a Japanese automotive gasoline-engine-oil standard for ultra-low-viscosity lubricants. The 2019 version established GLV-1 for SAE 0W-8 and 0W-12 oils; the 2024 framework also identifies GLV-2 categories. A GLV marking is an application-specific performance claim, not permission to use ultra-low-viscosity oil in an engine that does not require it.
Why JASO M 364 was created
Passenger-car engines increasingly use lower-viscosity oil to reduce pumping and friction losses. Earlier API and ILSAC categories did not initially cover every ultra-low-viscosity grade used in Japanese vehicles. JASO M 364 created a defined route for oils intended for these applications rather than forcing them into a category that did not describe their viscosity range.
The standard combines physical and chemical limits with engine and bench performance requirements. That distinction is important. SAE 0W-8 or 0W-12 describes a viscosity grade, while JASO M 364 addresses whether a formulation also meets defined fuel-economy, wear, oxidation, sludge, deposit, and related performance requirements.
JASO's implementation system also provides rules for filing formulations and displaying the performance classification. The mark is therefore more than an informal phrase printed on a label.
GLV-1 and the 2024 GLV categories
| Category | General role | Selection rule |
|---|---|---|
| GLV-1 | Ultra-low-viscosity gasoline engine oils, historically focused on SAE 0W-8 and 0W-12 | Use only where the vehicle manufacturer specifies the grade and category |
| GLV-2A / GLV-2B | Categories identified in the 2024 implementation framework, distinguished by the applicable fuel-economy test route | Verify the exact label, filing, vehicle requirement, and current JASO documentation |
The GLV letters and numbers should not be interpreted as a simple quality ranking. Each category belongs to a defined test framework. A product meeting another modern gasoline-oil category may still lack the exact JASO M 364 claim needed for an ultra-low-viscosity application.
What the standard evaluates
JASO implementation documents describe a suite of performance areas rather than a single fuel-economy test. These include fuel-economy performance, high-temperature oxidation, low-temperature valve-train wear, sludge control, timing-chain wear, phosphorus retention, volatility, foaming, and chemical limits. The exact methods and limits depend on the standard revision and filing route.
Fuel economy is evaluated under controlled conditions so that a candidate oil can be compared with reference oils. Wear and deposit tests address the concern that reducing viscosity must not eliminate essential protection. Chemical limits help manage compatibility with emissions systems and modern engine designs.
Passing a standard does not mean every oil produces identical results. It means the formulation met the applicable limits. Product selection still depends on the manufacturer's specified grade, category, and service interval.
JASO M 364 compared with API SP and ILSAC categories
API and ILSAC gasoline-engine-oil categories cover broad market requirements and recognizable certification marks. JASO M 364 was developed to address ultra-low-viscosity needs that were not fully represented when GLV-1 appeared. The categories can share test technology and performance concepts, but they are not interchangeable labels.
An oil may carry more than one claim when the formulation and licensing rules permit it. Conversely, an API-certified oil in a familiar viscosity grade should not be assumed to meet GLV-1. Read the complete back label and technical data, then compare it with the owner manual.
Do not use an ultra-low-viscosity grade merely because it may improve fuel economy in a compatible engine. Bearing clearances, oil-pump strategy, temperature control, variable valve systems, and durability validation are part of the engine design.
How to read a JASO M 364 label
The implementation manual specifies how the GLV category and filing information are displayed. A buyer should look for the stated category, the JASO M 364 reference, and the company guaranteeing the performance. The product name and viscosity grade should match the technical data sheet.
A phrase such as “suitable for ultra-low-viscosity applications” is not as specific as a filed GLV performance claim. If the wording is unclear, consult the lubricant supplier and the current JASO on-file information. Counterfeit or incomplete labels should not be used as the basis for engine service.
Because standards are revised, note the publication and on-file dates in JASO documentation. A current manual may introduce categories or procedures that did not exist when an older vehicle handbook was printed.
Application and service guidance
- Identify the exact engine, model year, market, and owner-manual revision.
- Confirm that SAE 0W-8, 0W-12, or another ultra-low grade is explicitly permitted.
- Match the required JASO category and any API, ILSAC, or OEM claim.
- Verify the product's filing or approval wording.
- Follow the manufacturer's drain interval and oil-level procedure.
- Use the specified filter and check for leaks after service.
Ultra-low-viscosity oils can move quickly through small clearances, so correct fill quantity and leak inspection remain important. Overfilling is not a way to compensate for lower viscosity. Underfilling reduces the oil reserve and can expose the pickup during vehicle motion.
Handling ultra-low-viscosity oil correctly
Use clean, dedicated dispensing equipment. Residual higher-viscosity oil in a pump or transfer container can alter the fill, while water and dirt can be especially harmful in engines with fine oil-control passages. Keep the container sealed and identify partial containers by product and opening date.
Measure the fill according to the vehicle procedure, start the engine only after confirming the drain plug and filter, then allow the specified settling time before the final level check. A fast-pouring oil can make careless filling easier, so add the final amount gradually. Do not judge the grade by appearance or pouring feel.
If the wrong viscosity was installed, consult the vehicle manufacturer or qualified service information. The safest response depends on how far the engine ran, temperature, load, and the oil used. Do not rely on additives or a thicker top-up to manufacture the required GLV formulation inside the crankcase.
Keep service records that identify the exact oil and category. This prevents a later technician from confusing GLV-1 with a similarly named viscosity product and provides context if consumption, pressure, or analysis trends change. For warranty-sensitive work, retain the invoice and product data sheet.
Recheck the oil requirement whenever the vehicle receives an engine replacement, software campaign, or revised service bulletin. The badge on the vehicle does not identify every running change.
For workshop inventory, separate ultra-low-viscosity products from conventional 0W-20 and 5W-30 oil. Similar container designs increase selection risk. Barcode or part-number controls, shelf labels, and a second verification at the vehicle reduce misfills. Update digital service menus when a new GLV category enters the fleet.
Frequently asked questions
What viscosity grades are associated with GLV-1?
The JASO M 364:2019 framework identifies GLV-1 for SAE 0W-8 and 0W-12 oils. Always verify the current revision and the vehicle requirement.
Is JASO M 364 the same as API SP?
No. They are separate standards and licensing or filing systems. Some performance concepts overlap, but one claim does not automatically prove the other.
Can I use 0W-8 to improve fuel economy in any modern engine?
No. Use 0W-8 only where the vehicle manufacturer explicitly permits it. Ultra-low viscosity is part of an engine-specific design decision.
What does GLV mean on the container?
It identifies a gasoline-engine-oil performance category administered under the JASO M 364 implementation framework. Check the complete marking and filing information.
Technical resources