* Jetta 2.5L: This base model came with a 2.5-liter inline-five cylinder engine producing 170 horsepower and 177 lb-ft of torque.
* Jetta TDI: This model came with a 2.0-liter turbocharged four-cylinder diesel engine producing 140 horsepower and 236 lb-ft of torque.
So, depending on the trim level, the base engine size for the 2011 Volkswagen Jetta was either 2.5 liters or 2.0 liters.