The 2-liter to 2.5-liter category goes to Audi's 2.5-liter turbo. With direct injection and a turbocharger, this five-cylinder engine produces 315 horsepower, yet has achieved over 30 mpg in European fuel economy testing.
May 18, 2011 1:09 PM PDT
Photo by: Audi
| Caption by: Wayne Cunningham
Conversation powered by Livefyre