Over the intervening years, four cylinder engines have gone from 31.1 percent to 37.9 percent of the U.S. market. Six cylinders retain the lead (for now!) with 39.8 percent while V-8s have dipped to only 20.4 percent of all installations. That trend is a big part of why GM recently chose to cancel a new premium V-8 engine program. At the Detroit Auto Show, Ford announced their EcoBoost engines that would be migrating into many of their cars in the next few years. The EcoBoost engines use reduced displacement along with direct injection and turbocharging. EcoBoost V-6s will replace V-8s while fours will replace V-6s. Similarly GM is going to downsized turbocharged fours as well as adding their second generation mild hybrid system to replace larger engines.
[Source: Winding Road]