How to Choose the Correct Engine Oil for Your Car

Start with the vehicle handbook

The single most reliable source for choosing engine oil is the vehicle manufacturer's handbook. It states the required SAE viscosity grade (such as 5W-30 or 10W-40) and the minimum performance specification (such as an API or ACEA level). Everything else — brand, price, marketing claims — comes after these two requirements are met.

In Bangladesh, many vehicles are reconditioned imports. If the handbook is missing, the manufacturer's official website or an authorized workshop can confirm the correct grade for your exact engine and model year.

Understand the two numbers that matter

The SAE grade describes how the oil flows when cold and at operating temperature. The specification level (API, ACEA or an OEM approval) describes the quality and protection standard the oil meets. An oil can have the right viscosity but the wrong specification level — both must match your engine's requirement.

• SAE grade — e.g. 5W-30: '5W' is cold-flow behaviour, '30' is hot viscosity.
• API level — e.g. API SN or SP for petrol, CI-4 or CK-4 for diesel.
• ACEA level — European classifications such as A3/B4 or C3.
• OEM approvals — manufacturer-specific standards listed on the oil's data sheet.

Match the oil to local driving conditions

Dhaka traffic means long idling, short trips and high ambient temperatures — conditions that work oil hard. Sticking to the manufacturer's recommended grade and changing oil on schedule matters more in stop-and-go city driving than on the highway. When in doubt, change earlier rather than later.

Buy authentic, buy from authorized sources

Counterfeit lubricants are a real risk in the market. Buying MANNOL products from MANNOL Bangladesh's authorized dealer network is the simplest way to be sure the oil in the bottle matches the label. If a price looks too good to be true, it usually is.