Americans want power, and Detroit knows it. Despite tough fuel-economy and emissions regulations, the Big Three are finding themselves in the position of ramping up production of their ever-more-powerful vehicles, while their most fuel-efficient models languish on dealers' lots. The most robust segment of the market is full-size pickup trucks and sport/utes-and those big, slab-faced beasts with V-8s (or V-10s) in their noses don't exactly sip dead dinosaurs. Power is what America wants and what it buys.
The 10 most powerful American-built '96 models gathered for this test produce an average of 310 horsepower. In model year '89 (hardly ancient history) the most powerful American production car was the L98 5.7-liter V-8 Corvette, and it made only 245 horsepower. But the horsepower explosion of the '90s doesn't stop with this elite group; everything is more powerful. Consider that the 2.5-liter DOHC V-6 in the '96 Ford Contour produces 20 more horsepower than did the 5.0-liter V-8 in the '90 Ford Crown Victoria (150 to 170).
Back when fuel economy and emissions weren't great concerns, the way to make more power was to burn more fuel, and the easiest way to burn more fuel was to increase engine displacement. For instance, when Cadillac introduced its revolutionary overhead-valve V-8 in '49, the engine displaced 331 cubic inches and produced 160 gross-rated horsepower. Two decades of power-lust later, the biggest '70 Caddy V-8 still had an OHV valve train and a carburetor, but displaced 500 cubic inches and made 400 gross horsepower. Today, displacement has given way to efficiency, and Cadillac's 279-cubic-inch (4.6-liter) Northstar V-8 produces 300 net horsepower (equivalent to about 400 gross) through the use of four-cam multivalve technology, advanced materials, and electronic engine controls.
Efficiency hasn't eliminated character. Although eight of the 10 engines motivating America's Most Powerful are V-8s and the other two are closely related V-10s, these powerplants are quite diverse.
The latest Corvette LT4 version of GM's 5.7-liter (350-cubic-inch) corporate small-block V-8 is rated at more than twice the net output it had when this basic engine was introduced in the '55 Chevy. Back in '55, the 162 gross horsepower (about 130 net) emerging from the original 265 cubic inches was a revelation. Breathing through a tiny Rochester carburetor and running a puny 8.0:1 compression ratio, it was the most powerful, popularly priced vehicle on the market.
Much of the '96 Corvette LT4's might comes from the small-block's thorough LT1 update in '91. The engine-block architecture remains very much the same as it was in '55 (cylinder bores are still spaced 4.4 inches apart), but the LT1 adopted reverse-flow cooling, redesigned aluminum cylinder heads, a crank trigger ignition, and advanced computer and fuel-injection technology to facilitate up to a 10.4:1 compression ratio and 300 horsepower in the standard Corvette.
The new LT4 in the Corvette Grand Sport expands upon the LT1's themes with a bump in the compression ratio up to 10.8:1 and a boost to 330 horsepower. Meanwhile, the LT1 has been revised for '96; the adoption of OBD-II engine electronics and a twin-catalyst exhaust system has produced an extra 10 horsepower (to 285) in Camaros and Firebirds. Furthermore, the SLP-supplied WS6 package on Firebirds and SS components on the Z28 bring out another 20 horsepower via cold air inhalation and an even freer-flowing exhaust. The LT1 in the Impala SS finishes its few remaining days with the same 260 horsepower as in '95.
The GM small-block is nearing its first half century in production, but it's still thrilling. With great low-end torque and a traditional V-8 rumble, it feels like a proper American engine should. The feel is distinctly U.S.A.