Automakers have vastly improved 4-cylinder engines over recent years so they are more powerful and run smoothly but still get good fuel-economy. These engines, not hybrid and electric vehicles sold in small numbers, will help meet new fuel-efficiency and carbon emissions standards for several years.
Background
4-cyls were 30% of U.S. new vehicle market in 2005
8-cyl fell from 26% to 16% from 2005 to 2010
New cars and trucks in U.S. must average at least 34.1 mpg by 2016
Cars will need to improve to 37.8 mpg to meet carbon cutoff