* Audi A3 2.0T: This model comes with a 2.0-liter turbocharged four-cylinder engine (TFSI).
* Audi A3 1.9 TDI: This model comes with a 1.9-liter turbocharged diesel engine (TDI).
The 2.0T engine is the most common base engine for the 2006 A3 in the United States, while the 1.9 TDI was more popular in Europe.
It's important to note that there might be variations in engine size and specifications depending on the trim level and region.
