The Auto Industry Diet

It’s no secret that more stringent fuel economy and emissions regulations are causing carmakers to think twice about the large vehicles and big engines in their fleets. Some consumers fear that we might be doomed to a Matchbox-sized future, with most Americans forced to drive tiny Smart-sized cars, and Mini Clubmans doing stand-in duty for limousines.

Truth is, car companies are smarter than that, and they’ve got plenty of ways of improving efficiency. We’re not just talking about building hybrids and electric vehicles, but technologies in both engine design and body construction that can help any vehicle get more mpg’s. So while smaller cars will indeed become more prevalent, larger vehicles won’t go the way of the brontosaurus.

Small Engines, Big Power

?An outdated axiom says that little engines are cheap, economical, and not very powerful. Traditionally, the smallest engine in a vehicle's lineup is the "base" engine, while larger, more powerful engines motivate premium or sporty editions. But this is changing: GM and Ford are both introducing vehicles that have bigger engines as standard, with smaller and more economical engines as options. Sometimes the smaller engines even deliver more power.

The all-new 2011 Chevrolet Cruze is arriving in dealerships as you read this. Its base engine is a 1.8-liter four-cylinder that produces 136 horsepower and 123 lb-ft of torque. The optional engine, however, is a 1.4-liter four-cylinder engine, turbocharged to make 138 hp and 148 lb-ft of torque. So even though it's smaller, the 1.4-liter is more powerful and it also delivers better mileage: 24 mpg city and 36 mpg highway, compared to 22 and 35 mpg. In what may be a major change for consumers to comprehend, car buyers will have to pay more for the smaller, turbocharged engine.

Ford is on a similar path. The 2011 Edge has a 285-horsepower, 3.5-liter V6 as its standard engine. But Ford has announced it will also be offering its 2.0-liter EcoBoost four-cylinder in the two-ton crossover. So how can such a substantial vehicle be powered by such a small engine? The EcoBoost four-cylinder combines a turbocharger with direct fuel injection (where the gasoline is carefully sprayed directly into the engine's combustion chamber) to produce approximately 230 horsepower and 240 lb-ft of torque. Ford hasn’t finalized its numbers yet, as this engine won’t be available until later in the model year, but performance should be close to that of the standard V6, while Ford says fuel economy will improve by at least 10 percent.

In a similar fashion, Ford will offer a 3.5-liter EcoBoost V6 with all the trimmings, including twin turbochargers, four valves per cylinder, direct fuel injection and variable valve timing on its legendary F-150 pickup. This engine is based on the one used in the high-performance Ford Taurus SHO, where it produces 365 hp. Ford says its engineers beefed up the engine for truck use with sturdier components and 25 percent more turbo boost. At this point, it has not announced the power rating, but Ford has said that the new EcoBoost F-150 will be rated to tow 11,300 pounds. This is the same as the 2011 F-150's optional 6.2-liter V8, and 1,500 pounds more than the standard 5.0-liter V8. The kicker is that the 3.5-liter EcoBoost truck engine should deliver a 20 percent improvement over the outgoing 2010 F-150's 5.4-liter V8. Not bad for a full-size truck that can tow your house off its foundation.

Weight Down, Economy Up

Manufacturers are also paying even more attention to cutting weight in their vehicles. In some cases this is a side benefit of reducing engine size – Ford says its 2.0-liter EcoBoost is 55 pounds lighter than a comparable V6 engine. Hyundai made the decision for its 2011 Sonata to do away with an optional V6 entirely, which it says allowed the company to design the front end in such a way that it saved over 100 pounds.

In many cases, weight reduction takes the form of using different materials than plain old sheet metal and steel. A favorite of carmakers is aluminum, although it has its own drawbacks, like higher cost and greater difficulty in stamping and welding operations. The industry pioneer in using aluminum for lightweight body construction is Audi, which builds several models with all-aluminum bodies, including the sporty R8 and the all-new 2011 A8 sedan. Compared to conventional steel-bodied luxury sedans in its class, the A8 weighs hundreds of pounds less, helping the Audi make due with a smaller standard engine that delivers better fuel economy.

There are dozens of examples of using lighter materials to be found throughout the industry, like the rear hatch of the Lincoln MKT crossover. Made of aluminum and even lighter magnesium, it weighs 22 pounds less than a conventional panel. While this might not seem like much, that's about what a battery or spare tire weighs, so it's significant. When combined with other lightened components, weight savings can add up to big fuel savings.

Not all weight cutting involves using aluminum. Plastics have made huge inroads into automotive manufacture over the past two decades. Even steel has gone “high-tech,” with manufacturers ranging from Kia to Mercedes-Benz using so-called “high-strength” steels in virtually all new vehicles. These are steels that are manufactured with higher quantities of certain elements to make them stronger than conventional carbon steel. Because of higher strength ratings, engineers can use less high strength steel to perform the same job as regular steel. One particularly tough amalgam is boron steel, which automakers use in key body areas that need to be strong to protect passengers. High strength steel is also a key to helping small cars achieve acceptable crash ratings.

While designing parts and vehicle systems to reduce their mass isn’t nearly as sexy or easy to sell to the consumer as a flashy new, high-tech engine, it’s a crucial component of meeting future fuel economy regulations.