What is the most efficient engine size for an Audi A4?

I am considering buying an Audi A4, and I want to know what the best engine size is for optimal performance and fuel efficiency.

The most efficient engine size for an Audi A4 is the 2.0-liter turbocharged four-cylinder engine. It offers a good balance of power and fuel efficiency.

If you prioritize performance over fuel efficiency, the 3.0-liter V6 engine would be a better choice. It offers more power but sacrifices some fuel efficiency.

For the best fuel efficiency, consider the 2.0-liter four-cylinder diesel engine. It has lower emissions and higher fuel economy ratings than the gas engine options.