Motorcycle Glossary

Engine oil

In Turkish: Motor yağı

In short

Engine oil lubricates, cools and cleans the engine's moving parts; on most motorcycles it also lubricates the clutch and gearbox.

Three things matter when choosing oil:

Viscosity (SAE): e.g. 10W-40 – the figure before "W" describes cold flow and the second figure the thickness at operating temperature.
Performance class: API (e.g. SL, SN) and, for motorcycles, JASO (MA, MA2, MB).
Base: mineral, semi-synthetic or fully synthetic.

On wet-clutch motorcycles, car oils with friction modifiers can make the clutch slip; use a JASO MA/MA2 approved oil. The change interval depends on the model; on small engines it is typically 3,000–4,000 km and at least once a year. Change the oil filter at the interval in the manual too.