Facing competition from hybrid and electric powertrains, the internal combustion engine is striking back. In recent years, automakers have developed gasoline-powered cars with mpg ratings that rival their alternative-fuel equivalents.
Hybrid and electric cars are expensive to produce. So improved internal combustion engines, even with the steep research and development costs, are an attractive proposition for automakers. And with sales of alternative fuel vehicles still modest, manufacturers need to produce high-selling fuel-efficient vehicles in order to meet increasingly stringent federal fuel economy standards that mandate fleet averages of 35.5 mpg by 2016.
“[Automakers] are trying to meet their numbers in a way that will allow them to still make a profit and sell their cars at a reasonable price,” said Joe Wiesenfelder, executive editor at Cars.com. “They recognize that volume is where the difference is going to matter.”
Take Chevrolet’s plug-in hybrid Volt hatchback. It boasts triple the mpg of even the most efficient of Chevy’s Cruze sedans: 98 mpg equivalent for the Volt compared with 33 mpg combined city/highway for the Cruze. But last year, almost 238,000 Cruzes sold compared with 23,461 Volts. All those Cruzes significantly reduce the fleet’s average mpg.
Automakers have boosted the efficiency of internal combustion engine-powered vehicles by various means. Turbochargers and direct injection (sometimes together) have allowed smaller engines to deliver 4-cylinder fuel economy with performance traditionally associated with V-6 mills. Improved automatic transmissions with higher gear counts allow for very efficient cruising and decent low-speed acceleration.
“That is one of the reasons why automatics are now often as efficient as manual transmissions in the same car,” Wiesenfelder said. “In a lot of cases, more efficient.”
Automakers have trimmed weight from vehicles by using lighter materials like aluminum and composites. Refined aerodynamics and low-rolling-resistance tires have further improved fuel economy.
The introduction of ultra-low sulfur diesel fuel in 2006 has enabled clean diesel vehicles to become contenders for drivers’ attention after decades of being seen as noisy, dirty and slow.
“They tend to deliver a lot of the advantages of the hybrid in terms of efficiency,” Wiesenfelder said. “[But] for me, the modern diesels are better to drive than hybrids.”
Even General Motors, which hasn’t offered a diesel passenger car for over a quarter century, is releasing the Chevrolet Cruze Clean Turbo Diesel this year.
Hybrids can still cost 20% more than their internal combustion engine-powered equivalents. For example, the 2013 Honda Civic Hybrid, which achieves 44 mpg highway, has a base MSRP of $24,360, while the gasoline-powered 41-mpg highway version starts at $19,765.
Diesel cars generally cost more than their regular gasoline-fueled counterparts but less than equivalent hybrids. The 2013 Volkswagen Jetta TDI Clean Diesel starts at $22,990, compared with $15,545 for a base gasoline model and $24,995 for the Jetta Hybrid.
Here are some internal combustion engine-powered cars that deliver at least 40 mpg highway.
Ford Focus SFE
($18,295 28/40 mpg city/highway)
Available only as a six-speed automatic, the SFE (Super Fuel Economy) package includes low-rolling resistance tires, aero wheel covers and a rear spoiler for just $95 over the MSRP of the regular Focus SE sedan. “Even in the SFE version, the Focus is really fun to drive,” Wiesenfelder said.
Volkswagen Jetta TDI Clean Diesel
($22,990; 30/42 mpg)
The Jetta TDI is one of a thrifty family of similarly engined VeeDubs that includes the Golf TDI, Passat TDI and VW-owned Audi A3 TDI. “I’m a big fan of these,” Wiesenfelder said. “I believe that the success of Volkswagen diesels, both in their execution and their success in the market, is what has given other manufacturers the confidence to give [diesels] a try.”
Chevrolet Cruze ECO
($19,680 28/42 mpg)
“A very nice, quiet, comfortable car,” Wiesenfelder said. “It’s unfortunate that you’ve got to get the manual [transmission] to get the most efficient version.” Even more eco than the Eco, the imminent Cruze diesel, starting at $24,885, claims 46 mpg highway.
($16,000; 31/40 mpg)
While the manual transmission version of the super-cute 500 achieves 40 mpg highway, that figure is arrived at by pumping premium gasoline into its fuel-saving (and emissions-reducing) 1.4-liter MultiAir motor. “It is a small, light car, which helps a lot,” Wiesenfelder noted. “[But] vehicles that are short from bumper to bumper and tall don’t always get the mileage you would expect.”
Honda Civic HF
($19,765; 29/41 mpg)
With low-rolling resistance tires and aerodynamic enhancements, including a decklid spoiler and smoothed-out front bumper, the HF “feels a lot like the regular Civic automatic,” Wiesenfelder said. Honda’s Eco Assist System, which monitors and displays the effect of driving style on fuel economy, encourages frugal habits.
Dodge Dart Aero
($19,295; 28/41 mpg)
This techie, peppy four-door boasts active grille shutters that automatically close at higher speeds to reduce drag, along with underbody aero treatment. Though American-built, the Dart shares architecture with its Italian Alfa Romeo Giulietta corporate cousin and a premium-gas-recommended MultiAir engine (albeit turbocharged) with the Fiat 500.