* US Market:
* 1.8T: This is a 1.8-liter turbocharged 4-cylinder engine with 170 horsepower. This was the base engine for the 1.8T, GLS, and GLX trims.
* European Market:
* 1.6L: A 1.6-liter naturally aspirated 4-cylinder engine with 102 horsepower was the base engine for some European models.
* 2.0L: A 2.0-liter naturally aspirated 4-cylinder engine with 115 horsepower was also common in Europe.
Therefore, the base engine size of a 2004 Volkswagen Passat can be either 1.6L, 1.8T, or 2.0L, depending on the specific trim and market region.
It's important to check the vehicle's specific documentation or a reliable online resource like the Volkswagen website or Edmunds to confirm the exact engine size for your particular model.
