WITH OIL prices reaching new highs and concerns about global warming growing, carmakers are racing to redesign petroleum-powered vehicles to run on less gas. Among those efforts are plans to equip gas-electric hybrids with advanced batteries that can be charged overnight from an ordinary electrical socket. Such “plug-in hybrids” promise huge gains in fuel efficiency but how many miles per gallon are they expected to run?
Answers: A. 25; B. 40; C. 100
A. 25 is not correct. The existing U.S. auto fleet averages about 25 miles per gallon (10.6 km/l), according to the Union of Concerned Scientists and the U.S. aims to improve that average in new cars to 35 miles per gallon (14.9 km/l) by 2020.
B. 40 is not correct. While the average new passenger car sold in the U.S. is required to get about 28 miles to the gallon (11.9 km/l), the gas-electric hybrid Toyota Prius and Honda Civic reach over 40 miles per gallon (17 km/l).
C. 100 is correct. The next generation of hybrid cars is expected to run on lithium-ion batteries, which can provide two to three times more power and weigh 50 per cent less than today’s nickel-metal-hydride batteries. If drivers regularly recharge their batteries at home, such plug-ins may get well over 100 miles per gallon (42.5 km/l).
