Which Audi A4 engine is best for fuel efficiency?

I am looking to purchase an Audi A4, but want to make sure it is fuel efficient. Which engine option is the best for fuel efficiency?

The 2.0-liter 4-cylinder engine is the most fuel efficient option, with an EPA-estimated 27 city/35 highway mpg. However, keep in mind that using premium fuel is recommended for this engine.

Also, make sure to stay on top of routine maintenance for optimal efficiency.

The 3.0-liter V6 may have a higher starting price, but it offers a respectable 23 city/34 highway mpg. Additionally, this engine pairs well with Audi's quattro all-wheel drive system for enhanced stability and traction.