What is the difference between the Audi A4 and A3 engines?

I am looking to purchase an Audi but can't decide between the A4 and A3. What are the main differences between their engines and which one is better suited for a city driver?

The major difference between the Audi A4 and A3 engines is the size and power. The A4 comes with a 2.0-liter four-cylinder engine, whereas the A3 comes with a 1.4-liter four-cylinder engine. As a city driver, the A3 may be a better option as it is more fuel-efficient and has a smaller size for navigating through traffic.