Here's a breakdown:
* 2.0L 4-cylinder: This engine is the base option, but it was only available in the Passat GLS trim level. It produces 115 horsepower and 125 lb-ft of torque.
* 1.8T 4-cylinder turbocharged: This engine was the base option for most trims, including the Passat, GLS, and Wagon trims. It generates 170 horsepower and 184 lb-ft of torque.
So, to determine the base engine size, you'll need to know the specific trim level of your 2005 Passat.