Police vehicles serve many functions. They are symbols of law and order that help deter motorists from speeding and other people from committing serious offenses. They're also rolling offices for sworn personnel, equipment haulers, and prisoner transportation systems. The list of all the tasks required of police vehicles could go on for a long time.

Because police vehicles are used for a variety of operations, the definition of what constitutes a "police car" is changing. It used to be that when the average American heard the words "police car," he or she would picture a large, four-door American-made sedan. Today, not all police cars are the same, nor are they all sedans.

For the 2005 model year, Chevrolet, Chrysler, and Ford have marketed police vehicles in all shapes and sizes. Special service vehicles include pickup trucks, SUVs, and even a station wagon. There's even a Chevy Tahoe SUV that's rated as a pursuit vehicle. And rightfully so; it can hit 124 mph.

Pursuit Vehicles

You can't just slap a lightbar on a civilian Ford Crown Victoria or Chevy Impala sedan and call it a police pursuit vehicle. A true police pursuit vehicle is outfitted with heavy-duty suspension, an engine that can take the stress of long hours of idling and driving at high speed, and heavy-duty electric systems that can handle the power demands of all the equipment that contemporary cops need on the job.

Here's a quick look at the 2005 police pursuit vehicles that are readily available in the United States.

Chevrolet Impala 9C1

Now that Dodge has ceased production of the Intrepid police vehicle, Chevy's Impala is the only U.S.-produced front-wheel-drive car designed for police duty. Any cop who has ever driven the police Impala will tell you that it is quick and nimble. For example, the combination of power rack-and-pinion steering and front-wheel-drive gives the Impala a turning radius of 38 feet.

As with any vehicle, opinions on the Impala differ greatly, but one thing it can't seem to overcome in the eyes of street cops is that it looks small. In this case, looks are deceiving. The Impala 9C1 is really only a little more than four inches shorter in wheel base and a foot shorter in length than the Ford Crown Vic. That may sound substantial, but it should be noted that front seat headroom and legroom is roughly comparable between the two cars.

Ford Crown Victoria Police Interceptor

The Crown Vic Police Interceptor is so ubiquitous in police service that speeding motorists have learned to scan their rearview mirrors for the car's distinctive grill design. This Ford sedan is exactly what most Americans picture when they hear the words "police car."

For 2005, the Police Interceptor is available in two axle ratios: 3.27:1 and 3.55:1. Unless you're a real gear head, you may have a hard time telling the difference between the two. Performance testing conducted by the Michigan State Police last year revealed that the primary benefit of the 3.55:1 Police Interceptor is a slight improvement in off-the-line acceleration. Specifically, the 3.55:1 model is about four-tenths of a second faster from zero to 100 mph.

Chevrolet Tahoe PPV

For years, agencies have needed a spacious police vehicle that can haul it down the road. For many of these agencies, the Tahoe PPV with two-wheel-drive may be the answer. The "PPV" in the police Tahoe's designation stands for "Police Pursuit Vehicle," and the word "pursuit" is not in the name just for marketing.

This SUV is fast. At last year's Michigan State Police tests, the Tahoe PPV achieved a top speed of 124 mph, only 4 mph slower than the standard Ford Crown Vic and only 1 mph slower than the Chevy Impala. The Tahoe is not just fast, it's quick. Its zero-to-sixty score at the Michigan test was faster than the standard Crown Vic Police Interceptor and the Impala.

Of course, achieving that kind of speed with a 5,000-plus-pound vehicle requires a serious engine. So the primary tradeoff for all this cargo space is fuel economy. The EPA rates the Tahoe at 16.5 miles per gallon, the Impala at 23, and the standard Ford Police Interceptor at 18.[PAGEBREAK]

Special Service Vehicles

One thing to remember when discussing contemporary police vehicles is that not all cop cars and trucks are going to be used to chase down speeding motorists.

Vehicles are used by law enforcement agencies for a wide variety of tasks. These special service vehicles are not designed or even modified specifically for police duties, but they can do certain jobs that pursuit vehicles can't.

The following is a quick look at some civilian vehicles that have been pressed into police duty.

Chevrolet Tahoe 5W4-4WD

When Chevrolet introduced the Tahoe pursuit vehicle last year, one of the questions on many officers' lips was, "Is it four-wheel-drive?" No. It isn't. But the Tahoe 5W4-4WD special service vehicle is.

This powerful four-wheel-drive SUV with a four-speed automatic transmission and overdrive is ready for offroad duty and it is suited for work in any road condition. The Tahoe 5W4-4WD offers 10.7 inches of ground clearance and state-of-the-art suspension for managing tough terrain.

Ford Explorer 4.6L SFI

The special service version of the Ford Explorer is on duty with a wide variety of law enforcement agencies worldwide. Explorers have been outfitted for K-9 units, SWAT teams, prisoner transport, and other duties. The police service Explorer is powered by a 4.6-liter, 281-cubic-inch engine that generates 239 horsepower at 4,750 RPM. With the rear seat folded down, this Explorer can haul 88 cubic feet of cargo.

Chevrolet Silverado 6.6L EDID 4WD

Agencies needing a rugged, off-road truck may want to take a look at Chevy's 4WD Silverado 6.6L EDID (Electronic Direct Injection Diesel). This light truck generates 310 horsepower at 3,000 RPM. All that power is transferred to the wheels through an Allison 1000 five-speed automatic transmission.

Ford Expedition 5.4L 3V SMFI

There are bigger vehicles available for law enforcement duty than the Ford Expedition, but they generally have heavy armor or more than four wheels. The Expedition weighs nearly 5,500 pounds, empty.

And it offers a lot of space to fill. Folding down the rear seat gives you more than 110 cubic feet of cargo space. Of course, there are also some tradeoffs. With a top speed of 99 mph empty, no one will mistake the Expedition for a pursuit vehicle, and it's not known for sipping gas.

Dodge Magnum 3.5L SPFI

The Magnum doesn't really take a bow in the police market until later this year when the 2006 model year Magnums are released as pursuit vehicles. But at the International Association of Chiefs of Police show and at the Michigan State Police tests last year, the 2005 Magnum with the standard 3.5-liter engine was on display.

Classed as a special service vehicle at the Michigan tests, the standard Magnum was still impressive. It clocked a top speed of 117 mph and its 3.5-liter engine generated 250 horsepower at 6,400 RPM. EPA mileage ratings on the Magnum are also noteworthy. Despite a curb weight of 3,904 pounds, the Magnum recorded 19 miles per gallon in the city, 27 highway for a combined score of 25.4.

The Magnum has a lot going for it, but it is a little different. Some officers may not like driving a station wagon, for example. But it should be noted that the design of the Magnum gives it nearly seven feet more of cargo capacity over the Ford Crown Vic and nearly nine feet more than the Chevy Impala.

In 2006, the Magnum pursuit vehicle will be available in two versions: the standard 3.5-liter sequential port fuel injection model and the thunderingly powerful 5.7-liter HEMI V-8 with cylinder deactivation, which produces 340 horsepower.