The nation’s fleet of new vehicles is on the verge of an extensive overhaul. Specifically, V8 engines soon could end up on the endangered-species list. New regulations require automakers to boost their fleetwide fuel economy incrementally, starting with 2012 models, to achieve an average 37.8 mpg for passenger cars and 28.8 mpg for pickups, SUVs and vans by 2016. This is a 40 percent increase over the current standards.
The V8 engines that can be found in a few 2011 passenger cars might be the last of their kind. So take a long, fond look at the Buick Lucerne, Chrysler 300 and Dodge Charger family sedans, and the eight-cylinder powerplants that continue to be available in the sports-car and luxury segments and among full-size pickups and sport-utility vehicles.
Automakers will turn to smaller engines to help to meet the stricter rules—although alternative powertrains will become more prevalent.
“Gasoline engines will still power 80 to 90 percent of vehicles all the way through 2025,” predicts George Peterson of researcher AutoPacific Group.
POWERFUL CHANGES. Thanks to direct fuel injection and turbocharging, smaller engines can be as powerful as larger ones are. Direct injection enables fuel to be shot into an engine’s cylinders at a greater-than-normal pressure and with more precision. This boosts fuel economy by up to 3 percent. Direct injection also allows a turbocharger to work more efficiently.
Last year, Ford introduced a 3.5-liter direct-injected and turbocharged V6 engine in its larger vehicles, including the Ford Taurus, which typically would come with a V8. In the Taurus, this “EcoBoost” V6 produces a V8-like 365 hp, but the vehicle is rated at 17 city/25 highway mpg, which is the same as a comparable model that is fitted with a 263-hp V6.
Although Buick and Hyundai risk alienating buyers who associate strong acceleration with large engines, their 2011 Regal and 2011 Sonata, respectively, eschew V6 upgrades in favor of turbocharged four-cylinder engines. The Sonata’s optional 2.0-liter, turbocharged four-cylinder engine generates 274 hp and gets 22 city/34 highway mpg. By contrast, the 2010 Sonata’s optional V6 generates 249 hp and gets an estimated 19 city/29 highway mpg. Upgrading to the V6 in the 2010 Sonata costs an extra $2,000; the SE trim level on the 2011 Sonata and its turbocharged engine costs just $1,550 more—and it includes automatic climate control.
Save Fuel: Shut Off the Engine
Analysts say high-tech engines will proliferate in the coming years. “The ‘new math’ is that four cylinders plus a turbo equals six or eight cylinders; six plus a turbo equals eight or even 12 cylinders,” says Philip Gott of research firm IHS Automotive Consulting. This means that larger cars will be able to use smaller engines for increased fuel economy with little, if any, loss in performance.
“When a vehicle is just going down the road in a straight line, the total power demand is on the order of 20 to 30 hp,” Gott explains. “Any extra power we need beyond that is to enable a vehicle to accelerate quickly from a stoplight or to pull a trailer up a hill . . . a vehicle can get by with a relatively small engine as long as it can deliver the maximum power [via turbocharging] when you need it.”
A smaller engine also means that a vehicle weighs less than it would otherwise.
“All else being equal, decreasing a vehicle’s weight by 10 percent enables about a 3 percent increase in fuel economy,” says Marc Ross, who is a professor of physics at University of Michigan. “Installing a more efficient engine that’s able to maintain the same level of performance at the lighter weight will result in around a 7.5 percent [fuel] savings.”