In light of the above, we offer the following predictions as to some new faces you're likely to see pop up on the SUV market during the not-too-distant future.
Beyond 2000: Look for Ford and Chrysler to come out with Contour- and Neon-based, respectively, CR-V fighters. Also, the popular Ford Explorer gets a modest facelift, more power, and additional creature comforts. Chevrolet will unveil an upscale edition of the Blazer, possibly called the TrailBlazer. The rumor mill says Toyota will produce an SUV based on its new-for-'99 T-150 full-sized pickup for '01. Meanwhile, Ford's highly anticipated mega-SUV will debut sometime after Jan. 1, 1999, probably as a '00. Bigger than a Suburban, it's based on the Ford Super-Duty trucks and will seat up to nine people. Engine lineup is likely to include a 5.4-liter SOHC V-8, 6.8-liter SOHC V-10, and 7.3-liter diesel OHV V-8. By '01, BMW will debut a car-based, on-road-oriented "Sport/Activity Vehicle," and Porsche will reveal its SUV.
Understanding All-Wheel Drive Vs. Four-Wheel DriveWith apologies to Jeff Foxworthy, if you've ever debated the distinctions between all-wheel drive and full-time four-wheel drive for more than an hour, you might be an auto writer. Or a truck division assistant brand manager. Certainly most sport/utility vehicle owners don't care what their drive system is called, so long as it gets them out of tight spots and deep mud. Better topics: How do the various 4WD/AWD systems work, and when can and-more important-can't 4WD/AWD help?
Though agreement on definitions is far from universal and some systems blur the differences, part-time 4WD systems need a pull of a lever or push of a button to send power to all four wheels. Those called AWD continuously distribute torque to all four wheels even on dry pavement without driver interaction. Some systems that could be labeled AWD are called full-time 4WD, and vice versa, though the latter often have the low-range gearing usually lacking with AWD. On-demand 4WD (aka automatic 4WD) sends virtually all engine torque to one axle until wheelspin is sensed, at which point a portion of the power is diverted to the opposite axle. If you think the latter sounds a lot like AWD, you're not alone.
How does 4WD (or AWD) work? The transfer case (or, for AWD, center differential) takes power from the transmission and apportions it to front and rear axles. How much torque goes to which axle depends on the system and the conditions: Some part-time 4WD systems send no more than half the torque to each axle regardless of what the other end is doing, while more modern systems divert all torque to the axle with the most traction.
Engaging low-range 4WD sends engine power through another set of gears that multiplies torque. This gear reduction causes the engine to rev about twice as high for a given road speed, offering a mechanical advantage for pulling and engine braking for descending steep, off-road trails.
When set in 4WD Auto, Ford's Control-Trac system-an on-demand 4WD system-sends 96 percent of engine torque to the rear axle until the computer senses wheelspin. Then a magnetic clutch in the transfer case engages instantaneously and diverts torque to the front axle.
Regardless of what you call the system, the primary purpose of sending power to all wheels is to aid forward traction in low-grip situations. Four- or all-wheel-drive can't increase cornering traction or braking power, or offer immunity from the laws of physics. Think of it this way: If your foot is off the gas, your SUV doesn't remember it has 4WD. While 4WD or AWD can help you climb a steep, snowy hill, it won't help you stop or go around a corner while descending the other side of the mountain. Also, SUVs' higher center of gravity, extra weight, and off-road-oriented tires mean these vehicles can have less cornering power and longer stopping distances than comparable sedans and minivans: 4WD or AWD won't-no, can't!-make up for this. Still, 4WD or AWD is an excellent tool if you understand the limits of its capabilities.-Mac DeMere