Engine oil

What it does

Lubricates and cools the moving parts inside the engine.

Signs it needs replacing

• Reached the change interval
• Oil below the minimum mark
• Oil looks black and gritty

What to tell the shop

• Vehicle make, model and model year
• Engine size, and whether it is manual or automatic
• The number printed on the old part, or a photo of it
• Whether you want genuine, OEM or a local replacement