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2012 Michigan State Police Tests: They Are “All In”
Written by Staff LAW and ORDER
Each year since the 1978 models, the Michigan State Police has tested a variety of police package (pursuit capable) 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, Mich. The vehicle dynamics testing are performed on the 2.0-mile road course at Grattan Raceway near Grand Rapids, Mich.
Performance-wise, this year was a slugfest between three very different sedans: the Dodge Charger 5.7L HEMI® V8, the Chevrolet Caprice 6.0L V8 and the Ford Sedan Police Interceptor 3.5L EcoBoost V6. The acceleration, top speed, braking and race course lap times were extremely close for all three of these sedans. Likewise for the group of V6 (or non-turbo) versions of these sedans. So close…so very close.
It won’t be performance that will be a deciding factor among these patrol vehicles. All the 350 hp V8 or V6 sedans perform the same. All the 300 hp V6 sedans perform the same. Instead, the decisions will be based on front seat room, rear seat room, trunk space, fuel economy and bid price.
This year, the MSP tested 15 police package sedans, and five police package SUVs-crossovers. Some of these were the same sedan and engine but used a different axle ratio, or were running on E85 ethanol. Last year, the MSP tested prototype versions of the Ford Sedan (Taurus) Police Interceptor and Utility (Explorer) Police Interceptor. This year, those were full production vehicles, marketed as 2013 models. There were no 2012 model Police Interceptors.
The MSP did not test any special service package (not intended for pursuit) vehicles like the 4x4 Tahoe, Expedition or Suburban, and they did not test any special-service package pickups. This remains an emphasis that the special service package vehicles are not designed for, nor intended for, emergency or pursuit driving. Only the emergency-driving, pursuit-capable vehicles, identified as such by the respective carmakers, undergo MSP testing.
2012 Police Vehicles
From Chevrolet, the police package sedans included the Caprice PPV powered by the 6.0L V8, in both gasoline and E85 versions; and the Impala 9C1 powered by the new 3.6L SIDI V6, in both gas and E85 versions. Their police package SUV, the Tahoe 5.3L V8 2WD, also used both gas and E85.
From Dodge, the police package sedans included the Charger Pursuit powered by the 5.7L V8 with both 2.65 (standard) and 3.06 (optional) axles; and the Charger Pursuit powered by the 3.6L Pentastar V6 with both 2.65 (standard) and 3.07 (optional) axles. The Charger V6 with the 2.65 axle was also run on E85.
From Ford, the police package sedans were all variations on the Sedan Police Interceptor with the 3.5L V6: FWD, AWD, EcoBoost AWD and the standard AWD run on E85. Its police package crossover, the Utility Police Interceptor 3.7L V6, was tested in AWD (standard), FWD, and AWD with E85.
The acceleration is recorded in 10 mph increments from 20 mph to 100 mph. The score for the event, however, is based on the zero-to-100-mph times. The tests are conducted slicktop, with no spotlights and with two troopers on board.
Of all the gasoline-powered sedans, the two fastest accelerating sedans were the Charger 5.7L V8 with the 3.06 and 2.65 axle, respectively. The Caprice 6.0L V8 and the Ford Sedan PI 3.5L EcoBoost were just a one-half second behind.
Of the 300 hp V6 sedans, about four seconds behind the 350 hp sedans, were the Caprice 3.6L, Impala 3.6L, Charger 3.6L and Ford Sedan PI 3.5L. Of the SUVs-crossovers, the Ford Utility PI 3.7L was in the same group as the V6 sedan, clearly ahead of the Tahoe 5.3L V8. For the record, the slowest of all the vehicles tested was three seconds faster to 100 mph than last year’s now-discontinued Ford CVPI. In fact, the average V6 sedan was fully five seconds faster to 100 mph than the Ford CVPI.
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 until they hit the electronic top speed limiter or the vehicle obviously stopped accelerating. All police and special service vehicles are electronically speed limited for reasons that include tire speed ratings, but not all vehicles actually reach that preset, limited speed.
The Chevy Caprice 6.0L V8 turned in the highest top speed at 154 mph. The Charger 5.7L reached 152 mph (2.65) and 151 mph (3.06). The Ford Sedan PI EcoBoost, Caprice V6, Impala V6 all ran between 148 and 149 mph. That was expected from the twin-turbo Ford, but this kind of top speed was a pleasant surprise from the Caprice and Impala with the new Camaro-Cadillac V6.
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.
For the 2012 model year, the MSP is changing its brake test protocol. It will now be a 10-stop series of ABS braking from 60 mph staring with cold brakes. This will be repeated twice. This kind of testing more closely mirrors actual pursuit conditions where the police vehicle involved in the pursuit starts off with patrol temperature (cool) brakes.
The testing will show braking performance as heat is steadily added to the braking system. 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 best braking performance, for the second year, came from the Caprice, first the 6.0L V8, then the 3.6L V6, at between 125 and 126 feet. The Charger 3.6L V6 and Charger 5.7L V8 were 127 and 130 feet. The Ford Sedan PIs recorded a 130- to 132-foot stop. The Ford Utility PI slightly outbraked the Chevy Tahoe in the 132- to 134-foot range.
The Grattan Raceway is a two-mile, 13-turn, road-racing course with a 3,200-foot front straightaway. By the end of the straight, for example, the Charger 5.7L reaches 120 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 the track, the suspension almost completely bottoms out. Each car is driven eight laps by four different MSP troopers from the Precision Driving Unit. The fastest five laps are averaged for the final score.
The road course times are the best overall assessment of the police vehicle. The road course incorporates acceleration, braking and cornering all into one number. A shortcoming in any one area will show up in the lap times. The separate tests for acceleration and braking will simply identify the area the road course times tell us exists somewhere.
On the road course, the fastest police package vehicle was the Charger 5.7L V8 in 3.06 axle, followed by the Charger 5.7L V8 in 2.65 axle. The Ford Sedan PI 3.5L EcoBoost V6, and Caprice 6.0L V8 were very close behind. In a cluster right behind these 350 hp sedans were three 300 hp sedans: the Charger V6 in 2.65 axle, the Charger V6 in 3.08 axle, and the Caprice V6. The Ford Utility PI 3.7L was much faster than the Tahoe 5.3L around the road course.
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 their part, regardless of vehicle platform, the MSP is careful to point out these tests (the minimums, the maximums and the category weights) are all designed for the way the MSP uses its highway patrol vehicles. Other departments will certainly use their vehicles in different ways, and this should put a different emphasis on the test results.
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 are probably very different. While subtle changes have taken place from time to time, the MSP typically weighs the tests as 30 percent for the road course, 20 percent for acceleration, 20 percent for braking, 15 percent for top speed, 10 percent for ergonomics and 5 percent for fuel economy. These numbers are plugged into a bid adjustment formula available at the NLECTC website.
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. Since most bids are close, this change in weighting may point to a different “most bang for the buck” police vehicle.
Photos courtesy of Larry Lee.
Published in Law and Order, Nov 2011
Rating : Not Yet Rated
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