In a move to boost overall fleet fuel economy numbers, more carmakers have turned toward small displacement turbo engines as a solution. But Consumer Reports just called foul on manufacturer claims that their turbos are more efficient and more powerful than larger displacement, normally-aspirated engines.

Consumer Reports singles out Ford's Fusion and Escape, Chevrolet's Cruze, and Hyundai's Sonata and Sportage — all of which are available with small displacement turbocharged models. Comparing them with normally aspirated cars like the Mazda3, Nissan Altima, and Honda Accord, all of which turned in higher fuel economy numbers in Consumer Reports' testing.

BMW was the only marque to improve acceleration and efficiency over conventional models with the turbocharged version of its four-cylinder engine.

Here's how a few of the cars they tested stacked up:

  • Mazda3, 2.0-liter four-cylinder (n/a): 32 mpg
  • Nissan Altima, 2.5-liter four-cylinder (n/a): 31 mpg
  • Honda Accord, 2.4-liter four-cylinder (n/a): 30 mpg
  • Hyundai Sonata, 2.4-liter four-cylinder (n/a): 27 mpg
  • Chevrolet Cruze, 1.4-liter four-cylinder (turbo): 26 mpg (27 mpg with Eco model)
  • Ford Fusion, 1.6-liter EcoBoost four-cylinder (turbo): 25 mpg
  • Hyundai Sonata, 2.0-liter four-cylinder (turbo): 25 mpg
  • Honda CRV, 2.4-liter four-cylinder (n/a): 23 mpg
  • Ford Escape, 1.6-liter EcoBoost four cylinder (turbo): 22 mpg
  • You can see the results of the other vehicles CR tested here

    Consumer Reports is also saying that the cars with normally-aspirated engines accelerated faster and more smoothly than their turbo cousins. It will be interesting to see what the touters of turbo have to say in their own defense. We're also curious about what octane fuel they were using and the conditions of their test track (these motors tend to do better on the highway).