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Michigan State Police 2009 Patrol Vehicle Tests

Written by PFM Staff

Each year since the 1978 models, the Michigan State Police has tested a variety of police package (pursuit capable) and special service package (not intended for pursuit) patrol vehicles. These annual tests include acceleration to 100 mph, absolute top speed, braking from 60 mph after brake warm-up, road racing course lap times, an ergonomic and communications installation review, and EPA fuel economy ratings.

The acceleration, top speed and braking phases are conducted at Chrysler’s Proving Grounds near Chelsea, MI. The vehicle dynamics testing are performed on the 2.0-mile road course at Grattan Raceway near Grand Rapids, MI. Of the 2009 models, the MSP tested six police package sedans and two police package two-wheel drive SUVs.

For the first time in more than a decade, the MSP did not test any special service package vehicles like the Explorer, Expedition, Suburban and 4x4 Tahoe. The Explorer was first tested by the MSP in 1996. Even when these special service package vehicles are tested, they are not run on the Grattan road course. This is an emphasis that the special service package, vehicles are not designed for or intended for emergency or pursuit driving. Only the pursuit-capable vehicles, identified as such by the respective car makers, undergo the high-speed, vehicle dynamics testing.

2009 Police Vehicles

The police package sedans included the 4.6L V-8 RWD Ford Crown Victoria Police Interceptor (CVPI) with the 3.27 axle ratio and the same car with a 3.55 axle ratio. These were both gasoline-powered CVPIs. All CVPIs can run seamlessly on E85. The RWD Dodge Charger was powered by both the 3.5L V-6 and the 5.7L V-8. The 3.9L V-6 FWD Chevrolet Impala was run in both E85 and gasoline versions. The only police package, pursuit-rated SUV is the 5.3L V-8 2WD Chevrolet Tahoe, and the MSP tested both gasoline and E85 versions.

Nearly all of the police and special service vehicles are carryover designs from 2008. Roof-rail airbags are now standard for the Chevy Impala and Tahoe in all versions. Police agencies cannot opt to delete them, so they must make sure that their prisoner partitions and other equipment are compatible with these airbags. The trunk cylinder lock is now standard on the Impala.

New for the 2009 Charger, the HEMI® engine has been tweaked for gas and performance issues. The addition of variable valve timing boosts horsepower and torque and the use of a lower axle ratio and wider setting for the cylinder shut-off mode increases fuel economy by about 4% with no loss in performance. Chrysler does not offer E85 FlexFuel in any of its police package vehicles.

A new paint system, which is expected to be running by February 2009, should allow for special paint schemes in batches of five cars, versus the 50-car minimum with the old painting system. Two new brown colors will also be added in 2009. For people concerned about what will happen to their Dodge Magnums, Chrysler assures them that the service support and parts will remain in place. The Charger and the Magnum have a shared platform, and many of the parts are the same or similar.

New on the Ford CVPI for 2009 are standard side airbags, providing both thorax and head protection for the front-seat occupants; power adjustable pedals; a revised antilock braking system (ABS), resulting in shorter stopping distances; and a revised engine-only traction control system that no longer engages the brakes. The confirmation flash that occurs when the doors are locked will now automatically be disabled when the courtesy lamp disable option (478) is ordered. In addition, the deck lid release button on the key fobs will be operational.

Production of the Ford CVPI, exactly as it is now, will continue through the 2011 model year.

Acceleration

The acceleration tests have maximum times allowed to reach 60 mph, 80 mph and 100 mph. The score for the event, however, is based on the 0-to-100-mph times. The tests are conducted slicktop, with no spotlights and with two troopers on board.

Of all the 2009 models, the fastest-accelerating was the HEMI-powered Dodge Charger—for the fourth year in a row. The 5.7L V-8 Charger reached 60 mph in 6.0 seconds. The HEMI Charger took just 14.3 seconds to reach 100 mph. In comparison, all the rest of the V-6 and V-8 sedans reached 100 mph in about 23 seconds.

The “green” question is, “How well do E85 ethanol-powered police vehicles run compared to the same vehicle on gasoline?” The E85-powered Impala was ¼ second faster to 100 mph than the gasoline version. The E85-powered Tahoe was likewise ¼ second faster to 100 mph than its gasoline-powered sister. Last year, the CVPI with E85 was ½ second faster to 100 mph than the CVPI with the same axle ratio running on gasoline. Forget the compressed natural gas (CNG) police cars from the 1990s. The E85-powered cars are as fast, or faster, than their gasoline-powered counterparts.

How does the acceleration compare among the V-6 Impala, the V-6 Charger and the V-8 Ford CVPI? The acceleration to 60 mph is just about the same. All these vehicles hit 60 mph in about 8.7-seconds. They all hit 100 mph between 22.2 and 24.1-seconds, with the V-6 Impala the fastest of the group, followed by the V-6 Charger and then the V-8 CVPI. The police package 5.3L 2WD Chevy Tahoe accelerated door handle to door handle with these sedans.

Top Speed

The second MSP test is top speed. At the end of the last acceleration run, the MSP troopers continue to accelerate the car around the 4.7-mile oval. The highest speed recorded anywhere on the course is the top speed of record. All police and special service vehicles are electronically speed limited, but not all vehicles actually reach that preset, limited speed.

The HEMI Charger, of course, had the highest top speed, which was limited to 146 mph. (An option on the HEMI Charger electronically limits the top speed to 132 mph.) The 3.9L Impala was close behind at 139 mph, while the V-6 Charger was close behind that at 136 mph. The two-wheel drive Tahoe reached 132 mph. The 3.27-geared CVPI ran 128 mph while the 3.55-geared Ford CVPI is limited to 119 mph for reasons of driveshaft harmonics.

A side note on these top speed tests: The police department may not see the same top speeds from the in-service car as these cars achieve during testing. The fully upfitted patrol car weighs much more than these cars as tested. The addition of spotlights and lightbars adds aerodynamic drag, and so does the addition of a front push bumper.

In some cases, depending on the extra weight and aerodynamic load, the car may or may not shift into the gear producing the most top speed, or may select a certain gear, hit the engine rpm limiter, and shut off without upshifting. If your department has a specific top speed the vehicle must reach, put it in the bid spec.

Braking

The MSP braking protocol involves two 90-mph, full-pedal stops to warm the brakes, followed by six 60-mph full-pedal stops for score. After a heat soak period, these two 90-mph and six 60-mph stops are repeated. The best 10 out of 12 stops from 60 mph are averaged for the final deceleration rate. This braking rate is converted to a projected stopping distance from 60 mph.

The MSP has established a maximum stopping distance for its large patrol sedans, both RWD (Ford CVPI, Dodge Charger) and FWD (Impala). The standard is about the same at 149.7 feet and 149.1 feet, respectively. All police package vehicles passed the MSP brake testing.

The best braking performance, now four years in a row, came from the Dodge Charger. Both versions of the Charger stopped in just 135 feet. This is very important because the brake pad compounds for the police Dodges was changed for 2008 to give longer pad life. Dodge has increased brake pad life without affecting braking performance. The Ford CVPI, 2WD Tahoe and V-6 Impala all stopped between 142 and 144 feet.

Road Course

The Grattan Raceway is a 2-mile, 13-turn, road-racing course with a 3,200-foot front straightaway. By the end of the straight, the 250-hp Ford CVPI, for example, reaches 110 mph. The course also has a number of twists and off-camber turns. On some parts of the track, the cars get nearly airborne while on other sections of track the suspension almost completely bottoms out. Each car is driven five laps by four different MSP troopers from the Precision Driving Unit.

On the road course, the fastest police package vehicle was the HEMI Charger. The Charger V-8 was a whopping 3¼ seconds quicker than the next closest cars, which were the V-6 Charger and the two Ford CVPIs. With overall lap times around 1 minute 40 seconds, the time interval between the HEMI Charger and the other sedans works out to a 17-car-length difference. After the three-vehicle pack of the V-6 Charger and Ford CVPIs, the V-6 Impala and 2WD Tahoe were a bit more than 2 seconds, or 10 car lengths, behind the V-6 Dodge.

The MSP does not test special service package vehicles, such as the Ford Explorer, Chevrolet Tahoe 4x4 or Ford Expedition on the road course. This is an emphasis that, in addition to clear and frequent written disclaimers from each manufacturer, these vehicles are not intended for high-speed, pursuit-style driving.

Fuel Economy

The Michigan State Police base their fuel economy rating on the EPA City mileage results. Fuel economy matters now more than ever. Because fuel economy is a tangible cost, unlike acceleration to 100 mph, for example, some fleet managers consider this operating expense on equal footing with the initial expense of the vehicle. They are not going to spend $0.15/gallon difference for a car that runs on premium fuel. Yet selecting a patrol vehicle with a 1.7-mpg difference in mileage is (cost-wise) the same as selecting an engine that runs on premium.

The MSP uses the EPA City rating for this aspect of its evaluation. In actual police service, no patrol vehicle ever gets EPA Highway mileage. However, under the revised EPA test protocol, some admin vehicles may achieve the City rating, and a few may even achieve the Combined rating. Expect 15% to 25% less mileage when running on E85 ethanol.

The Winners

Fleet managers divide police cars into so many categories, it is impossible to identify any one car as a “winner” based on the NIJ-funded MSP tests. Across the nation, fleet bid categories are subdivided into FWD and RWD, into V-6 and V-8, etc. The “winning” car, the car with the best overall performance may be the best V-6 powered sedan, or the best RWD sedan, or the best V-8 RWD sedan.
For its part, regardless of vehicle platform, the MSP is careful to point out that these tests (the minimums, the maximums and the category weights) are all designed for the way the MSP uses its patrol vehicles. Other departments will certainly use their vehicles in a different way, and this should put a different emphasis on the test results.

If some of the artificial bid distinctions are removed and instead the term “police package sedan” is used, a winner in sheer vehicle performance is obvious. The Charger V-8 has the fastest acceleration, the highest top speed, the quickest road course times and the shortest braking distances.

The MSP weighs the six test phases to suit the needs of a state police or highway patrol. The needs of city and county law enforcement agencies probably are very different. While subtle changes have taken place from time to time, the MSP typically weighs the tests as 30% for the road course, 20% for acceleration, 20% for braking, 15% for top speed, 10% for ergonomics and 5% for fuel economy. These numbers are plugged into a bid adjustment formula available at the NLECTC Web site.

Different weightings may be selected. For example, an urban department may want to emphasize fuel economy, ergonomics and braking while de-emphasizing road course, acceleration and top speed. Because most bids are close, this change in weighting may point to a different “most bang for the buck” police vehicle.

Photos by Larry Lee

Published in Police Fleet Manager, Nov/Dec 2008

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