It's long been tradition that big cars have big engines. But fuel-economy standards (in the US) and carbon emissions limits (in Europe) mean that even the big cars of tomorrow will have to use far less gasoline than they do today.
One way they'll get there is by radically downsizing the engines. Yes, diesel, hybrid, and electric powertrains will play a role as well. But don't kid yourself; the gasoline engine will be with us for decades to come. It's just going to get a lot more efficient.
EcoBoost: coming on fast and strong
In the first of several iterations, it's a 355-horsepower, 3.5-liter, twin-turbo V6 that will return "at least" 17 miles per gallon city / 24 mpg highway in the large, luxurious 2010 Lincoln MKS Sport--which previously would have had a V8.
Ford has recently said that by 2013--just three model years hence--more than 90 percent of its North American models will be offered with an EcoBoost engine option. That's much faster than last year's pace, when the company said it'd be half by 2015.
Get out yer wallets
But the smaller and more complex engines will cost more than bigger, simpler engines of the same power. It's noteworthy that the EcoBoost 3.5-liter V6 is the top-of-the-line engine in both the 2010 Lincoln MKS and the 2010 Ford Taurus SHO performance model.
Gasoline direct injection alone adds $122 to $525 to the cost of a car, according to an analysis from 2953 Analytics using data from the National Highway Traffic Safety Administration, cited in Automotive News. And you can add another $120 to $810 for a downsized, turbocharged engine.
Direct injection cuts fuel consumption by 1 to 2 percent, says the NHTSA, and downsizing plus turbocharging cuts another 5 to 7.5 percent.
Ford combines its engine with a six-speed automatic transmission ($161 to $262, for a 3 to 5 percent reduction) and other modifications to achieve total mileage gains of 20 to 30 percent.
Europeans go further yet
The Europeans are likely to take the downsizing trend much further. The Dutch AutoTelegraaf quotes Audi Group CEO Martin Winterkorn saying the next version of Audi's flagship--its large, luxurious 2011 Audi A8 sedan--will be offered in Europe with a 230-horsepower four-cylinder engine.
European versions of the current 2009 Audi A8 now offer engines from a 2.8-liter gasoline V6 to the massive 6.0-liter W12, along with V6 and V8 turbodiesels. In the States, we only see the 4.2-liter V8 or the big W12.
Audi is not alone. Eighteen months ago, Daimler pointed the way with its breathtaking Mercedes-Benz F700 Vision concept. That car offered the fuel economy of a 2009 Toyota Prius (42 miles per gallon) in a full-size sedan the size of today's 2009 Mercedes-Benz S550.
The F700 Vision uses a very advanced twin-turbo 1.8-liter four-cylinder engine in a hybrid-electric configuration. Executives we interviewed for a long profile of the car hinted that we may indeed see a four-cylinder in the S-Class Benz sometime in the future.
Diesels will get smaller too. At the recent 2009 New York Auto Show, a surprise "concept" appeared: the 2011 Mercedes-Benz E250 Bluetec, a brand-new E-Class with the smallest diesel Benz has shown here in decades. It combines a European 2.5-liter turbodiesel with the complex BlueTec emissions control system needed to meet stringent US regulations.
Even BMW has said its next M5 will replace the current turbocharged V10 with a fire-breathing turbo straight six. And Jaguar will likely combine a downsized engine with a hybrid system, as previewed by its LimoGreen research project with Lotus.
All sizes shrink (their engines)
Almost all car sizes will be affected as fuel economy rules tighten. The 2011 Chevrolet Cruze will use a 1.4-liter four fitted with a turbocharge and gasoline direct injection. It replaces the 2009 Chevrolet Cobalt, which sports a non-turbo 2.2-liter engine.
Result: Same performance, much better fuel economy.
At the lowest end, we may soon see cars with engines smaller than anything sold in the US since the Sixties. The 2011 Chevrolet Spark, for instance, could come with a 1.2-liter engine, the larger of two sizes it offers in Europe and Asia (the other is 1.0 liters).
2011 Mercedes E250 Bluetec