Subaru automobiles made in 2010 are fitted with either a 2.5-liter, four-cylinder engine or a 3.6-liter, six-cylinder engine. The 2.5-liter engine features a 3.92-by-3.11-inch bore and stroke. The 3.6-liter engine features a 3.62-by-3.58-inch bore and stroke.
Subarus with the 3.6-liter engine offer 256 horsepower and 247 pound-feet of torque. The Subaru Forester 2.5X Premium, Outback 2.5i Limited and the Subaru Legacy 2.5i feature the 2.5-liter engine but only offer 170 horsepower and 170 pound-feet of torque. The 2.5-liter, Forester 2.5XT Limited offers 224 horsepower and 226 pound-feet of torque, while the 2.5-liter, Legacy 2.5GT Premium offers 265 horsepower and 258 pound-feet of torque. The 2.5-liter models that offer more than 170 horsepower do so because they have been fitted with turbochargers.
Due to factors such as weight differences, the two Subaru engines used in 2010 may perform differently within the available models. In terms of fuel economy, models with the 3.6-liter engine offer 18 miles per gallon in the city and 25 mpg on the highway. The 2.5-liter models offer between 19 and 23 mpg in the city and between 26 and 31 mpg in highway driving, depending on the model.