More of the Best Tech

The automotive buyer’s guide published in the August issue of Popular Science featured a variety of key technologies consumers should know about when comparing new cars. What follows are additional categories likely to pique your curiosity in the showroom—diesel tech, off-road capability and all-important in-car entertainment options.

DIESELS
Tech
Diesel engines are more efficient and more powerful than their gas cousins. Built from heavier material than gasoline engines to withstand the higher pressure of self-igniting fuel (as opposed to spark-plug ignitions in conventional gas engines), they are able to withstand higher piston speeds. Longer connecting rods allow the pistons to build up more velocity in the cylinder, exerting greater leverage—and, as a result, higher torque—on the crankshaft.

Pacesetter
GMC Sierra 1500HD. There’s nothing torquier than GMC’s Sierra, with a beastly 6.6-liter Duramax turbo-diesel V8 that produces 640 pound-feet of torque. (Compare it with the Dodge Viper’s SRT10’s eight-liter engine, which is larger but â€only†produces 505 pound-feet of torque.) As a result, a Sierra HD with an Allison five-speed automatic transmission can tow as much as 16,700 pounds—say, a really big boat.

Other Options
The Mercedes E320 CDI and Volkswagen Passat TDI both use new high-pressure fuel injectors to more completely burn the fuel, resulting in quieter, more powerful but less smelly cars that you probably wouldn’t realize were diesel until you got to the pump—765 miles later, in the Mercedes’s case.

Bottom Line Although new technology has made diesels more powerful, quieter and less odorous, the U.S. market still isn’t quite ready for them. California passenger-car particulates standards, which have been adopted by seven other states, effectively ban them, so don’t expect to pick one up at your local San Diego car dealer. New standards for cleaner diesel fuel, to be introduced in 2007, will probably spur a more accommodating regulatory environment.

OFF-ROAD MONSTER
Tech
It takes a lot more than ground clearance to make a capable off-road vehicle. Four-wheel drive is a must have, but not all systems are well suited to leaving the tarmac: Serious off-road setups will sport selectable low-range gears that increase the number of engine rpm for each turn of the wheels, amplifying torque output at low speeds. A locking differential, which evenly distributes power among the four wheels, is also a must-have, because a system that diverts power away from slipping wheels would have a hard time figuring out where to send it when you’re driving through deep sand or loose terrain. And the most-boasted-of off-road feature is wheel articulation, the measurement of how far the wheels can travel, which translates into the ability to keep your wheels in contact with uneven terrain.

Pacesetter
Dodge Power Wagon. In a world full of off-roader wannabes, Dodge’s gargantuan new Ram Power Wagon is the real deal, packing a laundry list of serious off-road hardware, including electronically locking front and rear differentials, an electronically disconnecting front stabilizer bar and long-travel Bilstein dampers for increased wheel articulation, 33-inch BFGoodrich All-Terrain T/A rubber, a passel of underbody skidplates and tube-steel rock rails, and a 12,000-pound custom Warn winch to pull you out if things go south. Oh, and there’s a 345-horsepower 5.7-liter Hemi V8 to stir up some dust on the trail.

Other Options
Though considered luxury rides, Land Rover vehicles—in particular the Range Rover and the LR3—have impeccable off-road credentials. The company has a long history of producing incredibly durable vehicles for a variety of markets—it is perhaps most famous for its Defender 90, a no-nonsense off-road utility vehicle that is used around the world.

Bottom Line
All-wheel drive and four-wheel drive are not the same thing. Even though both power all four wheels, AWD is designed for slippery pavement, not muddy hill climbs or backwoods traveling.

DRIVING THEATER
Tech
Some vehicles, usually at the top trim levels, come with sensational rear-seat and in-dash entertainment packages that are factory-installed and fully integrated into car’s existing control system.

Pacesetter
Cadillac Escalade. The Escalade ESV Platinum Edition offers several forms of in-vehicle entertainment, including a Bose premium sound system with a six-CD changer and nine speakers, XM Satellite Radio and a dual-screen rear-seat entertainment system. This system has two seven-inch viewing screens—one for the second row and one for the third—and it comes with four wireless headphones.

Other Options
The eight-speaker Rockford Fosgate system in the new Mitsubishi Eclipse cranks out 650 watts and has a 10-inch subwoofer in the trunk. Also, many major manufacturers now offer factory-installed XM or Sirius satellite-radio systems—all you have to do is activate the account.

Bottom Line
The aftermarket is generally the best place to go for high-quality entertainment systems—it’s now even possible to get satellite television access in a moving car—so buy factory-installed units only if the dealer gives you a substantial discount or tosses them in free.

HOT CONVERTIBLES
Tech
You may think it’s there merely to keep you dry, but an automobile’s roof has significant structural importance. Building a convertible that can match a coupe for stiffness and handling poses a unique challenge. GM engineers designed the Kappa platform to be more than just the underpinnings of their new drop top. Its hydroformed steel frame rails are inexpensive to manufacture and provide excellent structural rigidity, especially when combined with Kappa’s wide stance.

Pacesetter
The Pontiac Solstice. The first car built on the Kappa architecture is wide and low to the ground—a distinct appearance melded with stability and responsive handling. Powered by a 2.4-liter variable-valve Ecotec four-cylinder engine that produces 177 horsepower and 170 pound-feet of torque, the Solstice has a top speed of 143 mph. Its wide wheel stance enhances handling, providing a smoother, more responsive ride.

Other Options
The Mazda MX-5 Miata. Since its debut in 1989, the Miata has been a lightweight sports car meant to be powerful and fun to drive. Its newest iteration has a 1.8-liter four-cylinder engine that makes 142 horsepower and 125 pound-feet of torque. Engineers worked on improving airflow in the cylinder head to get the most of the diminutive power plant, cutting intake restriction by 57 percent to keep the engine torque nearly level, even at high rpm. An ultrahigh-tension steel chassis provides stiffness and rigidity, and 50-50 weight distribution keeps it poised on the road.

Bottom Line
There’s more to a convertible than being able to go topless. A sports car provides an exhilarating burst of power and speed and a responsive, smooth ride. Subtle curves and stylistic nuances create a unique look for every model, and a wider vehicle means improved handling.