The 2006 list marks the 12th year for the Ward's 10 Best Engines program, the auto industry's highly anticipated annual barometer of powertrain prowess.
This year?s winners, as well as the vehicles tested, include:
Audi AG: 2L FSI turbocharged DOHC I-4 (Audi A3)
Audi AG: 4.2L DOHC V-8 (Audi S4)
BMW AG: 3L DOHC I-6 (330i)
DaimlerChrysler AG:5.7L Hemi Magnum OHV V-8 (Dodge Charger R/T)
Ford Motor Co.: 4.6L SOHC V-8 (Mustang GT)
General Motors Corp.: 2L supercharged DOHC I-4 (Chevrolet Cobalt SS)
General Motors Corp.: 2.8L turbocharged DOHC V-6 (Saab 9-3 Aero)
Mazda Motor Corp.: 2.3L DISI turbocharged DOHC I-4 (Mazdaspeed 6)
Nissan Motor Co. Ltd.: 3.5L DOHC V-6 (Infiniti G35 6MT)
Toyota Motor Corp.: 3.5L DOHC V-6 (Lexus IS 350)
Two important engineering developments are front and center for several engines on this year's list: direct-injection gasoline (DIG) technology and forced induction. These systems allow engineers to develop engines that generate startling power yet return acceptable fuel economy.
BMW 3L pays homage to inline-6 architecture.
DIG technology is emerging as one of the powertrain sector's most promising new developments. Injecting fuel directly into each of the engine's cylinders produces outstanding performance and emissions improvements for new-generation diesels. Engineers now are using the technology for gasoline engines to generate improved low- and mid-range torque and in many cases to conserve fuel.
DIG systems are featured on three of this year's 10 Best Engines winners.
The technology is widespread throughout Audi AG's engine lineup, and buyers of the entry-level A3 have access to this year's winning 2L FSI DOHC I-4.
The FSI system (an acronym for "Fuel Straight Injection"), combined with a sophisticated variable-geometry turbocharger, helps Audi's diminutive 2L powerhouse produce 100 hp per liter - an industry benchmark for performance.
Mazda Motor Corp. follows a similar formula for its winning 2.3L DISI DOHC I-4 powering the all-new Mazdaspeed6 sport sedan.
This new engine combines DIG technology and turbocharging to generate 274 hp - a remarkable 119 hp per liter. The engine produces a V-8 like 280 lb.-ft. (379 Nm) of torque and a respectable 19 mpg (12 L/100 km) in the city and 25 mpg on the highway (9 L/100 km).
Also employing DIG to astounding effect is Toyota Motor Corp. with its Lexus 3.5L DOHC V-6. Generating a new benchmark of 306 hp from its normally aspirated 3.5L, the new Lexus V-6 adds a novel approach of combining DIG with a conventional port fuel-injection system to deliver its high horsepower combined with an impressive EPA fuel economy rating of 21 mpg(11 L/100 km) in the city and 28 mpg (8 L/100 km) on the highway, along with Lexus' now-famous high levels of refinement.
"DIG technology is the most important development the powertrain sector has seen in this decade," says Bill Visnic, Ward's senior technical editor.
"Particularly combined with turbocharging, direct injection for gasoline engines is permitting engineers to design smaller, more power-dense engines that provide the ever-higher performance levels that customers have come to expect," Visnic says.
Audi turbocharged 2L makes A3 a joy to drive.
Cylinder deactivation, which allows an engine to operate with half its usual number of cylinders when full power is not necessary, is another recently developed fuel-saving technology that makes DaimlerChrysler AG's now-famous 5.7L Hemi V-8 even more attractive.
Winning a Ward's 10 Best Engines award for a fourth consecutive year, the 5.7L Hemi incorporates the company?s Multi-Displacement System to instantaneously shut down four of the engine's cylinders when not needed.
Meanwhile, when the Hemi's vaunted power is required, MDS immediately reactivates the cylinders to generate the engine's full power rating.
Superb V-8 performance also is at the heart of two returning 10 Best Engines winners.
Ford Motor Co.'s 4.6L SOHC V-8 is back as a winner for a second year following a significant design change that yields more horsepower and torque.
"Ford's 4.6L modular V-8 is a convincing modern-day interpretation of a muscle-car V-8," says Visnic. "But the engine shows its adaptability by being equally impressive in other Ford models, including its SUVs."
Audi enjoys its second 10 Best Engines winner for 2006 with its stellar 4.2L DOHC V-8. Racking up its third consecutive award, the Audi V-8 once again impressed Ward's testers with its remarkable blend of performance and refinement.
At 81 hp per liter, the Audi 4.2L V-8 remains at the forefront of the class of "premium" V-8s.
General Motors Corp. rings in with two winners of 10 Best Engines awards. GM makes serious inroads into the affordable performance market with its thrilling 2L supercharged DOHC I-4 used in the Cobalt SS performance coupe.
Thanks to supercharging and intelligent design, GM engineers squeeze more than 100 hp per liter from their 4-cyl. dynamo, while achieving a 23/29 city/highway fuel economy (10/8 L/100 km) rating from the Environmental Protection Agency.
Also enjoying a first win is GM's 2.8L turbocharged DOHC V-6, currently used exclusively by GM's Saab brand for its 9-3 sport sedan and wagon.
The 2.8L DOHC V-6 is a variant of GM's sophisticated "global" V-6 engine architecture, tuned in the Saab application for an outstanding mix of performance and refinement, while underscoring Saab's heritage for turbocharged engines.
"A sophisticated mid-displacement V-6 and turbocharging are a remarkably effective combination," says Visnic. "GM and Saab have created an impressive performance-car engine with high specific output and the thrill of turbocharging."
Supercharged 2L in Chevy Cobalt SS puts GM in tuner hunt.
Taking its unrivaled twelfth consecutive Ward's 10 Best Engines trophy is Nissan Motor Co. Ltd.'s 3.5L DOHC V-6.
The only engine to win a 10 Best Engines award every year since the program's inception, Nissan engineers improve the sterling "VQ" V-6 with new levels of power and torque for 2006.
Its 298 hp (as used in the Infiniti G35 with manual transmission) rivals or beats many V-8s, while delivering the levels of refinement that have been a hallmark of the "VQ" modular engine series since its inception more than a decade ago.
Ward?s 10 Best Engines list is completed by BMW AG's new 3L DOHC I-6. BMW engineers have dramatically improved the company's hallowed inline 6-cyl. design to produce more power while simultaneously delivering markedly improved fuel economy and reduced emissions.
True to BMW's heritage for sophisticated engineering, the new BMW 3L inline 6-cyl. employs an innovative new construction technique of magnesium and aluminum for the engine block that enabled significant weight reduction.
During a 2-month test period, six Ward?s editors evaluated engines from 31 different cars, trucks and SUVs. Scoring encompassed the crucial engine characteristics of power; torque; noise, vibration and harshness (NVH); technical relevance and basic comparative numbers. All engines nominated and tested were in vehicles with a base suggested retail price under $52,500.
Details of the 10 Best Engines will be featured in Ward's AutoWorld magazine, Ward's Engine & Vehicle Technology Update and on www.WardsAuto.com in January 2006.
Credit: Wards Auto - Primedia
Photo Credit: ClubLexus