- Engine Displacement**: The 4-cylinder models typically have a displacement of around 2.5 liters, while the 6-cylinder models have a displacement of 3.7 liters.
- VIN Number: The VIN number is a 17-character code that can be found on the driver's side door jamb. The 10th character of the VIN number indicates the engine type. If it is "4", your Mazda 6 has a 4-cylinder engine. If it is "6", your Mazda 6 has a 6-cylinder engine.
- Engine Cover: The engine cover of your Mazda 6 can also provide information about the engine type. If it has a 4-cylinder engine, it will typically have a "4" or "2.5L" badge. If it has a 6-cylinder engine, it will typically have a "6" or "3.7L" badge.