Which Engine Oil Does Your Bike Need? What the Owner’s Manuals Say

“Which is the best engine oil for my bike?” gets asked constantly, and most answers online end in a brand recommendation. The better answer is already in your glovebox: your owner’s manual names the oil grade, the specification and the quantity your engine was designed for. Here is how to read those numbers, and what six owner’s manuals from four manufacturers actually specify.

The short answer

• Use the grade (for example 10W30 or 20W50) and the specification (JASO and API) that your owner’s manual lists. Brand matters far less than matching those.
• Most geared motorcycles call for a JASO MA or MA2 oil. Many automatic scooters call for JASO MB. They are not interchangeable.
• Fill to the quantity and level mark in the manual. More is not better.
• If your bike is under warranty, check whether the warranty names a specific oil. Bajaj’s does.

How to read an engine oil label

The grade: 10W30, 15W50, 20W50

This is the oil’s viscosity rating under the SAE system. The number before the W describes how the oil behaves when the engine is cold (“W” stands for winter), and the number after it describes how thick it stays at normal running temperature. A 20W50 oil is thicker when hot than a 10W30. Your engine’s clearances were designed around the grade in the manual, so that is the one to use.

JASO MA, MA2 and MB

This is the specification that matters most on a two-wheeler, and it is the one most often ignored. In most geared motorcycles, the clutch runs in the same oil as the engine (a “wet” clutch). JASO MA and MA2 oils are made for that: they let the clutch plates grip properly. JASO MB oils are lower-friction and are used in many automatic scooters, where the clutch does not share the engine oil. Put an MB oil in a wet-clutch motorcycle and the clutch can start to slip.

API SL, SN

This is a general quality category from the American Petroleum Institute. Later letters are newer categories. Your manual lists the minimum it expects.

What the manuals specify

Each of these comes from the manufacturer’s own owner’s manual. Page numbers are the printed page numbers in each manual.

Bajaj Pulsar 150

• Grade and specification: SAE 20W50, JASO MA2, API SN. The oil named is Bajaj DTS-i 10000.
• Quantity: 1,000 ml at a routine refill (1,100 ml after an engine overhaul).
• Change: at the first service, then every 10,000 km, with a top-up at 5,000 km.
• Warranty note: the manual’s warranty conditions list using only the recommended Bajaj DTS-i 10000 oil at the specified interval.

Source: Pulsar 150 BS VI owner’s manual, pages 24 and 47. Full schedule: our Pulsar 150 service guide.

TVS Jupiter 125

• Grade and specification: SAE 10W30, API SL, JASO MB. The oil named is TVS TRU4 Skuuta.
• Quantity: 700 ml of engine oil, plus 120 ml of transmission oil (the same oil) in the separate gearbox.
• Change: engine oil at every service; transmission oil every 24,000 km.

Source: TVS Jupiter 125 owner’s manual, pages 72 and 74. Full schedule: our Jupiter 125 service guide.

Royal Enfield Hunter 350

• Grade and specification: SAE 15W50, API SL, JASO MA2, semi-synthetic.
• Quantity: about 1.7 litres at a refill (about 2.2 litres when the engine is completely dry).
• Change: at 500 km, then every 10,000 km, with the level checked every 1,000 km.

Source: Royal Enfield Hunter 350 owner’s manual, pages 22 and 85. Full schedule: our Hunter 350 service guide.

Royal Enfield Classic 350 (earlier carburettor model)

• Grade and specification: 15W50, API SL, JASO MA.
• Quantity: 2.30 to 2.50 litres at a refill (2.75 litres at first fill).

Source: Classic 350 owner’s manual, page 5.

Royal Enfield Classic 350 (current model)

• Grade and specification: 15W50, API SL, JASO MA2, semi-synthetic.
• Quantity: 1.7 litres at a refill (2.2 litres dry fill).

Source: Classic 350 BS VI owner’s manual (2025), page 19. Full schedule: our Classic 350 service guide.

Hero Splendor+

• Grade and specification: 10W30, API SL, JASO MA2 (Hero 4T Plus recommended).
• Quantity: about 0.85 litre at a drain and refill (1 litre after disassembly).

Source: Splendor+ owner’s manual, pages 5 and 31. Hero’s warranty terms exclude engines run on any other grade. Full schedule: our Splendor Plus service guide.

Notice the pattern: the five motorcycles all call for a JASO MA-type oil, and the automatic scooter calls for JASO MB. Notice too how different the quantities are. The Hunter 350 takes well over twice as much oil as the Jupiter 125, which is one reason service costs rise with engine size.

Mineral, semi-synthetic or fully synthetic?

Follow the manual here too. Royal Enfield specifies a semi-synthetic oil for the Hunter 350; the Bajaj and TVS manuals specify their own branded oils by grade and specification. A more expensive fully synthetic oil in the correct grade and JASO rating will not harm a bike, but it does not change the manufacturer’s change interval either, so do not use it as a reason to stretch one.

Common mistakes

• Using a scooter or car oil in a geared motorcycle. Car oils and JASO MB oils are not made for wet clutches.
• Going by the brand, not the label. The same brand sells several grades. Check the grade and the JASO rating on the bottle itself.
• Overfilling. Fill to the level mark. The TVS manual specifically warns that excess oil can cause leaks.
• Forgetting the scooter’s gearbox oil. Automatic scooters like the Jupiter have a separate transmission oil with its own, much longer, change interval.
• Stretching the interval. Oil ages with time as well as distance. Our guide to bike service intervals shows how the time limits work. If your mileage has dropped, see bike mileage dropping.

Checking the oil at your next service

Whoever services your bike, it is reasonable to ask which oil is going in, and to see the bottle. Check the grade and the JASO rating against your manual. On our doorstep services, no part or consumable is replaced without your approval, and the engine oil change is part of a general service. General service packages are priced by engine size, from up to 110 cc to up to 300 cc, with separate Royal Enfield packages. If your bike is still under warranty, read does doorstep bike service void your warranty? first.

Last updated: 22 September 2026. Oil specifications are taken from each manufacturer’s owner’s manual and can differ between model years. The manual for your own bike is the document that applies.