Which engine oil your bike needs: JASO MA2, grades and prices

The short answer

If your two-wheeler has a gearbox and a clutch, it needs a 4T engine oil marked JASO MA2, in the viscosity grade printed in your owner's manual. If it is an automatic scooter with a belt drive, it needs a scooter oil marked JASO MB. That is the whole decision, and getting it the wrong way round is the one mistake that costs money.

Castrol India sells both. Its Activ Scooter 10W-30 and 5W-30 are API SN and JASO MB, and Castrol states on its own product page that they are strictly not to be used in wet clutch motorcycle engines. The geared-bike range is the other way: Castrol POWER1 in India comes in 10W-30, 10W-40, 15W-40, Cruise 15W-50 and Cruise 20W-50, all listed as API SN and JASO MA-2. TVS, for its Sport commuter, names TRU4 Premium in SAE 10W-30, API SL, JASO MA2.

So the order of steps is simple. Open the manual, note the grade and the oil quantity, then buy a sealed pack of that grade that carries the JASO class your bike needs.

What the letters and numbers mean

SAE 10W-30 is viscosity. The 10W is how easily the oil flows when cold, the 30 is how thick it stays when the engine is hot. A 20W-40 or 15W-50 is a heavier oil, which is why big air-cooled singles and twins often ask for it, while modern four-valve commuters and most scooters are on 10W-30 or thinner.

API SL, SN or SP is the general service rating. JASO T 903 is the one that matters on a bike, because the clutch sits in the same oil as the engine. JASO MB is the low-friction class, with a dynamic friction index from 0.5 to under 1.45. MA is the high-friction class, and MA2 is its grippiest band: an oil must show a dynamic friction index of 1.8 or more, a static friction index of 1.7 or more and a stop time index of 1.9 or more, all under 2.5, to be classed MA2.

That is why a scooter oil in a geared bike can make the clutch slip under load, and why MA2 is what the makers specify.

What a bottle costs

Prices on Hero MotoCorp's own online shop give a fair idea of the official range. Hero 4T Plus 10W-30, API SL and JASO MA2, in an 800 ml pack is listed at ₹504, down from ₹560. The 900 ml 4T Plus Premium 20W-40 is ₹540, the 1,000 ml 4T Plus 5W-30 synthetic is ₹750 and the 1,250 ml Xotic Plus 10W-30 synthetic is ₹1,350. The scooter oil, the 800 ml JASO MB 10W-30, is ₹540.

Note the pack sizes. Commuters from 100cc to 160cc usually need under a litre, which is why 800 ml and 900 ml bottles exist. Buy the size your engine takes rather than a litre you half use. While you are there, front fork oil is ₹61 for 100 ml and ₹85 for 160 ml, and coolant is ₹330 a litre, both worth adding if a fork service or a top-up is due.

Checking the level, and when to change

Castrol's own method is worth copying. Park the bike on level ground, on a centre stand or paddock stand. If the engine has been hot, leave it at least 20 minutes to cool and let the oil settle back into the sump. Then read the inspection window on a modern bike, or pull the dipstick on an older one.

For the change interval, follow the service schedule in your manual and your service book, not a number off a forum. In an emergency, topping up with another brand of the same grade and the same JASO class is far better than riding low on oil.

Sources

• Castrol POWER1 two-wheeler oils, India
• Castrol Activ and Activ Scooter range, India
• Hero MotoCorp official shop: Hero Genuine lubricants
• JASO MA and JASO MB classifications and friction indices
• TVS Motor: most suitable engine oil for the TVS Sport
• Castrol: how to check motorcycle oil