The Popular Science Automotive Buyer's Guide

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Should you get a turbocharged four or a high-tech hybrid? A slick seven-speed automatic or a sequential manual? Will all-wheel drive really save your butt? You probably already know what type of vehicle you want—SUV, sedan, sports car—but understanding key automotive technologies in today’s cars can help you decide among competing models. Here, we dissect the critical innovations manufacturers are offering to enhance performance, safety or both.

POWER TO GO | ENGINES

Don’t let the showroom jargon scare you. The internal combustion engine still works as it always has; it’s just better. Modern refinements can make a huge difference in initial cost as well as operating cost, raising or lowering either, but they also greatly improve performance. Depending on the specific model and price, engines may have any of several enhancements—these are the four you should know about.

How many cylinders do you need?
For basic fuel efficiency, four-cylinder engines rule. But for real acceleration and easy cruising at high speed, get a turbocharged four, a six-cylinder or an eight. And a Hyundai V6 is nothing like an Audi V6—the simpler (and cheaper) 3.5-liter engine in Hyundai’s XG350 produces 194 horses, while the 3.2-liter power plant in the Audi A6 employs sophisticated engine-management systems to help generate 255 horsepower. In any case, you can stop at a V8—there are a handful of cars with V12s being sold in America, but there’s little they can do that a well-engineered V8 can’t, except make outrageous howling noises and gulp gas like it’s shooting out of a garden hose.

1.Variable Displacement
Tech
To improve gas mileage at highway speeds, certain engines can now deactivate half their cylinders—or just two. While the pistons continue to move inside the cylinders, fuel intake is shut off.

Pacesetter
Honda Odyssey. The sophisticated 255-horsepower 3.5-liter V6 in the Odyssey smoothly shuts down three of its six cylinders during highway cruising and deceleration, bumping up mileage by as much as 12 percent.

Other Options
Variable displacement works in muscle cars, too. The Dodge Magnum RT’s 340hp, 5.7-liter V8—as well as other Dodge and Chrysler Hemi engines—features a multi-displacement system that boosts fuel economy by 5 to 20 percent.

Bottom Line
Although the engines are prone to subtle audible variations between full and partial-displacement use, it’s barely noticeable. Honda, in fact, has equipped its benchmark van with noise-canceling technology, piped through the car’s stereo, to effectively mask any evidence of the system.

Honda Odyssey
Power 255 hp, 250 lb.-ft. of torque, V6
Performance 060 in 8.6 sec., 117 mph top speed
Price $34,700 (touring version)

2.Hybrids
Tech
To stretch fuel economy, true gas/electric hybrids run either with both the gas engine and the electric motor working in a partnership of varying power ratios, or on electric power alone. “Mild hybrids,” on the other hand, supplement gas engines with electric motors—adding horsepower without sacrificing fuel economy—but they can’t run on electricity alone.

Pacesetter
Lexus RX 400h. Using parent company Toyota’s technology, this true hybrid SUV combines a 3.3-liter gasoline V6 and a pair of electric motors. Its 268 hp and 212 pound-feet of torque thrust it to 60 mph in 7.3 seconds—half a second faster than its conventional sibling, the RX 330—while its fuel efficiency is a combined 29 mpg city/highway, a 38 percent improvement.

Other Options
The Honda Accord Hybrid gets a terrific boost from its electric motor, but test-drive it first—our sample vibrated slightly during engine shutdowns at stoplights.

Bottom Line
Most hybrid drivers are finding their real-world fuel economy to be lower than the Environmental Protection Agency estimates, which are based on outdated testing methods. Remember that hybrid efficiencies are greatest in urban driving—highway mileage is only slightly better.

Lexus RX 400h
Power 268 hp, 212 lb.-ft.of torque, combined V6 and electric motors
Performance 060 in 7.3 sec., 124 mph top speed
Price $49,200

3.Turbocharging
Tech
Using exhaust-driven fans—turbos—to compress air and force it into an engine generates a greater explosion inside the cylinder and, thus, more power. It’s an easy, inexpensive way to goose both small and large engines’ performance.

Pacesetter
Mitsubishi Lancer Evolution IX. For the ninth iteration of its hallowed Evo—a featherweight, all-wheel-drive sedan revered by rally fans and street racers—Mitsubishi squeezed another 10 hp out of the 2.0-liter inline four-cylinder engine, thanks largely to an innovative twin-scroll turbocharger that generates 20.1 psi of pressure inside the cylinders. The result is an astonishing 286 horsepower at 6,500 rpm, and 289 pound-feet of torque.

Other Options
The Porsche Cayenne Turbo’s V8 gets a turbo boost from 340hp to 450 hp, making it the world’s fastest SUV.

Bottom Line
For a performance car, natural aspiration remains the gold standard, because you have much faster and more linear engine response. But turbocharging is no slouch—turbo lag is mostly unnoticeable now, and manufacturers such as Audi, Porsche and Saab routinely turbocharge their lineups with impressive results.

Mitsubishi Lancer Evolution IX
Power 286 hp, 289 lb.-ft. of torque, inline 4-cylinder
Performance 060 in 4.4 sec., top speed unavailable
Price Not set at press time

4.Variable Valve Timing
Tech
Computer-controlled variable valve timing (VVT) smoothes out engine performance by optimizing the fuel and air mixture inside the cylinders at different engine speeds. Systems vary, but typically, at higher speeds, the intake valves open earlier, wider and for longer durations, delivering maximum fuel and air for increased power. At lower rpm, the overabundance of gas would be wasted and cause a rough idle, so the valves admit less.

Pacesetter
Ford Mustang GT. Its all-aluminum, 4.6-liter V8 employs a variable cam timing system that increases fuel efficiency, lowers exhaust emissions, and generates a robust power output of 300 hp and 320 lb.-ft. of torque.

Other Options
Most Hondas—the company that pioneered VVT—Toyotas and Nissans now feature VVT, as do many performance cars.

Bottom Line
This technology is a tremendous leap forward and is worth seeking out. Ford’s version is one of the simplest yet, making it an affordable option for carmakers and, ultimately, more accessible to consumers.

Ford Mustang GT
Power 300 hp, 320 lb.-ft. of torque, V8
Performance 060 in 5.1 sec., 147 mph top speed
Price $25, 200

Horsepower Versus Torque
We all drool over horsepower figures, but what is often more relevant is torque—how much force the car applies to the road. Horsepower helps maintain speed (high-horsepower engines really strut their stuff at triple-digit speeds), but torque determines whether the car can accelerate with gut-churning ferocity. The Mercedes E500 and Acura RL both have 300hp, but the V8 Merc has 339 pound-feet of torque, and a 5.8-second 060 time, while the V6 RL musters only 260 lb.-ft. of torque and a 6.6-second 0—60.

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