model year Prius yielded a five-star driver and four-star passenger rating in the frontal-collision test (out of five stars). Side crash results were four out of five stars for both front and rear seats. The car scored four out of five stars in rollover testing. US Insurance Institute for Highway Safety crash tests scored the Prius Good overall in frontal collisions and Good overall in side-impact collisions in models equipped with side airbags. A Poor score was given to models without side airbags. Side curtain and torso airbags became standard on 2007 American models. Official government fuel consumption data United States In the U.S., the Environmental Protection Agency (EPA) test results must be posted on new vehicle windows, and are the only fuel consumption figures that can be advertised. EPA testing procedures for all vehicles were revised in 2007 in an attempt to better match what the average driver would achieve. The following data is taken from the EPA figures for the Prius: city driving, highway driving, combined. United Kingdom The official UK fuel consumption data, provided by the Department for Transport, rates the Prius as: urban, extra urban and combined. Air pollution In the United States the EPA measures a vehicle's air-borne pollution based on hydrocarbons, nitrogen oxides, carbon monoxide, particulate matter and formaldehyde before assigning them a score. In most states the XW20 Prius is rated Tier II Bin 3. CARB also does its own emission scoring, the XW20 Prius meets AT-PZEV certification in California and states that adopted CARB emission rules. The second generation Prius tied with the MINI Cooper D as the fourth least -emitting vehicles at 104 g/km, behind the Ford Fiesta Econetic at 98 g/km and the tied Volkswagen Polo 1.4 TDI/SEAT Ibiza 1.4 TDI at 99 g/km. It is the least -emitting gasoline powered car (the Ford and the Polo/Ibiza run on diesel). Awards 2004 Motor Trend Car of the Year. 2004 Car and Driver magazine's Ten Best list. 2004 North American Car of the Year award. 2004 International Engine of the Year 2004. 2004 "Best Engineered Vehicle for 2004" by SAE's Automotive Engineering International magazine. 2005 European Car of the Year. 2006 EnerGuide Award (Midsize). 2006 Intellichoice Best Overall Value of the Year, Midsize. 2007 Intellichoice "Best in Class Winner": best retained value, lowest fuel, lowest operating costs, lowest ownership costs. 2007 Swiss government named Toyota Prius the world's greenest car in