EoW March 2012

Transatlantic cable † E ciently powerful 4-cylinders. An example of what is rapidly becoming the de facto con guration for small gasoline engines was found in the engine bay of the Cadillac ATS sedan: a 2-litre 4-cylinder engine incorporating twin-scroll turbocharging, direct fuel injection, a relatively high compression ratio, and low-friction internal parts. The engine layout of Cadillac’s rst 4-cylinder in more than 20 years is similar to that in certain Mazda, Ford and Honda models; † Divide and conquer. Typical of the latest turbocharged engines, the 201-horsepower 4-cylinder of the Hyundai Veloster Turbo is equipped with a twin-scroll turbocharger. By splitting the ow of exhaust gases between two passageways, twin-scroll turbos isolate cylinders whose exhaust pulses interfere. This makes for a more responsive engine by reducing the delay in building up pressure; Direct delivery. Hyundai says that its use of direct fuel injection, variable valve timing, and variable intake tuning in the Genesis Coupe’s 3.8-litre V-6 produces net gains of 42 horsepower and 29 pound-feet of torque. Peak horsepower is 348; torque tops out at 295 pound-feet. Direct fuel injection sprays fuel into the engine’s cylinders rather than into the passageways farther upstream, improving the precision of delivery and providing some cooling e ect; † Doing without a throttle. The new Dodge Dart uses Fiat’s MultiAir 2 valve-throttling system in two of its 4-cylinder engines (one of them from Fiat). Like the Valvetronic system that BMW pioneered ten years ago, MultiAir 2 uses the engine’s valves rather than a throttle plate to control air coming into the cylinder under certain conditions. Power losses resulting from the engine having to pull air past the throttle is reduced, engine e ciency enhanced;

† Double clutching. Another bene t to Chrysler of Fiat’s ownership comes in the form of Fiat Powertrain Technologies’ dual-clutch 6-speed transmission. Volkswagen pioneered dual-clutch transmissions in production cars nearly a decade ago, but only recently have they become common. Mr Stenquist wrote: “This technology o ers automatic shifting but provides better e ciency than conventional automatics because it assures a no-slip mechanical coupling of the engine to the gearbox rather than a uid coupling.”

Steel

However spectacular, the cars were not the whole show at Detroit

Materials – notably the lighter, pliable steel intended to outdo rival products in meeting the demands of the automotive industry – commanded much attention at the North American International Auto Show. In what the Wall Street Journal termed a ‘third wave’ in automotive steel, American producers are bending their e orts toward the development of advanced high-strength steel, employing continuous-annealing methods to modify its microstructure and thus its malleability and toughness. Success, if they achieve it, will pay o handsomely. The domestic steel industry’s biggest customers, US car makers were expected to produce 13.4 million vehicles in 2011, up from 10.4 million in 2009. But the makers of aluminium, plastics and sponge are in hot pursuit, pressing the claim that their products are more malleable and lighter – key considerations for design and fuel e ciency, respectively.

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EuroWire – March 2012