Hybrid City/Highway Efficiency
A combustion engine is inefficient in taking a heavy car from a stop all the way up to speed -- it burns a lot of gas. And in a city, you do that every five blocks or so. So a car powered only by a gasoline engine gets better mileage on the highway, where there are fewer stops and starts. A hybrid car can operate on electric-only at low speeds, so it's not burning gas during stops and starts. Also, every stop recharges the battery. Hybrids therefore get better city mileage than on the highway, where the combustion engine does most of the work.
Ford Escape Hybrid Specs
To improve efficiency in the gasoline engine itself, Ford used a four-cylinder Atkinson-cycle engine in the hybrid version of the Escape. Atkinson engines are more fuel efficient than standard-cycle engines (known as Otto-cycle engines) at the expense of horsepower. To learn about the Atkinson cycle, see Lindsay Publications: Atkinson Cycle Engine.
The Escape Hybrid's 2.3-liter, aluminum, four-cylinder, dual overhead cam engine generates 133 horsepower at 6,000 rpm. The three-phase, permanent-magnet, synchronous electric motor adds 94 horsepower in the 3,000-5,000 rpm range. By itself, the gasoline engine can crank out 129 lb-ft of torque at 4,500 rpm. (For comparison, the four-cylinder engine in the non-hybrid Escape generates 153 hp at 5,800 rpm and 152 lb-ft of torque at 4,250 rpm.)
The AWD Escape Hybrid weighs in at 3,893 lbs (1,766 kg) -- the hybrid components add about 500 pounds (230 kg) to the Escape's weight. With a wheelbase of 103.1 inches (261.9 cm) and an 8-inch (20-cm) ground clearance, it's a relatively compact SUV. The Escape rides on Continental ContiTrac EcoPlus tires (spare included). The fuel tank holds 15 gallons.
According to Car and Driver magazine (Dec. 2004), the AWD Escape Hybrid with a full options package accelerates from zero to 60 mph (97 kph) in 10.8 seconds, has a top speed of 102 mph (164 kph) and goes from 70 mph (113 kph) to a full stop in 195 feet (60 meters).
For anyone interested in buying a hybrid, one of the most important numbers is the fuel mileage. The Escape won't come close to the 50 mpg or more offered by compact hybrids. Ford rates it at 35 mpg in town, 29 mpg on the highway. Several different tests (USAToday, 5/13/04; Motor Trend, Aug. 2004) showed the real numbers will probably be a few miles per gallon lower, but the Escape Hybrid still offers a 20 to 25 percent increase in fuel economy over the non-hybrid Escape and a huge gain over larger SUVs that barely manage 10 mpg.
The Ford Escape Hybrid comes in either front-wheel-drive (FWD) or all-wheel-drive (AWD) varieties. The official EPA mileage rating for the FWD version is 33 mpg in the city and 31 to 36 mpg on the highway. For the AWD version, it's 33 mpg in the city and 29 on the highway. With those numbers, one tank of gas should give you a range of 400 to 500 miles (650 to 800 km).
Check out the next section to find out what it's like to drive an Escape Hybrid.