It's Fall 2007. The leaves have slowly started their turn into the colors of autumn; the weather has slowly shifted its gears, and geese have begun their long haul to a warmer climate. This also means the Police Vehicle Evaluation and Purchasing Program has gone into overdrive pushing 2008 police vehicle models to their utmost limit.
Knowing this limit allows law enforcement agencies to compare police vehicles side-by-side to enhance the decision in choosing the right vehicle for the right mission.
The program, sponsored by the Michigan Department of State Police, National Law Enforcement & Corrections Technology Center and Michigan Department of Management & Budget, began more than 25 years ago with the dedication to provide an objective look into the mechanical abilities that next year's new police vehicle models have to offer. The only limitations enforced are rain days and the fortunate absence of traffic in the testing. Testing included the standard evaluations the program has developed: driving dynamics, acceleration, top speed and braking. Drivers evaluated different models such as: general service, sedans and a sport utility vehicle (SUV); special Service, SUVs and a truck; and (for the second year) motorcycles. Ford, General Motors, DaimlerChrysler, Harley-Davidson and BMW put their police vehicle packages through the rigors of the police vehicle tests.
This year's general service category included:
- The Ford Police Interceptors 3.27 4.6L SPFI and 3.55 4.6L SPFI, both vehicles also with its equivalent E85 model;
- Chevrolet Impala (9C1) 3.9L SPFI;
- Chevrolet Tahoe PPV 2WD 5.3L SPFI and its E85 counterpart;
- Dodge Charger 3.5L SPFI and 5.7L SPFI; and
- Dodge Magnum 3.5L SPFI and 5.7L SPFI.
The special service category included:
- The Ford F-150 2WD Super Crew 5.4L SMFI;
- Ford Explorer 2WD 4.6L SMFI;
- Ford Expedition 2WD 5.4 3V SMFI;
- Chevrolet Tahoe 2WD 5.3L SPFI; and the
- Chevrolet Suburban 3/4 ton 4WD 6.0L SPFI.
The motorcycles included:
- The Harley-Davidson Police Road King;
- Harley-Davidson Electra Glide; and the
- BMW R1200RTP.
Acceleration, top speed, brake and motorcycle driving dynamics were tested at the DaimlerChrysler Proving Grounds in Chelsea, Michigan, Saturday, September 15, with the rain day Sunday, September 16. The Grattan Raceway Park in Grattan, Michigan, hosted the testing of the remaining vehicle's driving dynamics — save the special service vehicles, which were not involved in any driving dynamic testing — on Monday, September 17, that rain day being Tuesday, September 18.
The vehicle dynamics evaluation's objective was to compare each vehicle's high-speed pursuit-handling characteristics and performance. The 2-mile course is a road racing-type course containing hills, curves and corners and is 2 miles long. Simulating actual conditions encountered in pursuit situations in the field, with the exception of other traffic, the evaluation is a true test of the success or failure of the vehicle manufacturers in offering balanced packages in terms of their blending of suspension components, acceleration capabilities and braking characteristics.
All vehicles were driven over the course a minimum of 32 timed laps, using four separate drivers, each driving an eight-lap series. The final score for the vehicle is the combined average (from the four drivers) of the five fastest laps for each driver during the eight-lap series.
Two of the Dodge "team" came out on top by 2 seconds above the third-place vehicle. The Dodge Charger won with an overall average of 1:37.77 minutes, with the Magnum 5.7L not far behind at 1:37.94 minutes — a difference of only 17 hundredths (0.17) of a second. Following the Magnum in third and fourth were the Ford Police Interceptors 3.27 4.6L E85 model at 1:40.59 minutes and 3.55 at 1:40.70 minutes. The third Interceptor, the 3.27, took fifth place at 1:40.78 minutes.
Motorcycle dynamics held the last positions overall with the BMW leading the motorcycle group at 5:49.43 minutes. The Harley-Davidson models held a less than 2-second difference from each other with the FLHP Road King at 6:17.23 minutes and LHTP Electra Glide at 6:19.08 minutes.
See Table 1 on Page 49 for additional vehicle dynamic results.
The vehicle braking test's objective was to determine the deceleration rate attained by each test vehicle from 60 to 0 mph impending skid (threshold) stops, with the vehicle's anti-lock braking system (ABS) in operation, if the vehicle is equipped. Each vehicle was scored on the average deceleration rate it attained through 12 trials.
Each vehicle made two decelerations at specific predetermined points on the test road from 90 to 0 at 22 feet per sec.2, while using a decelerometer to maintain the target deceleration rate. Immediately after these "heat-up" stops were completed, the vehicle made six measured 60 to 0 mph impending skid (threshold) stops, again with ABS in operation, at specific predetermined points. Following a 4-minute heat soak, the entire sequence was repeated. The exact initial velocity at the beginning of each of the 60 to 0 mph decelerations and the exact distance required to make each stop was recorded by a Datron non-contact optical sensor with a personal computer. The resulting data calculated the average deceleration rate — the vehicle's score for the test.
In the general service group, the Dodge Magnum 3.5L stopped earliest at a project stopping distance (PSD) of 136 feet. Following directly behind is its counterpart 5.7L at a PSD of 141.1 feet. Creating Dodge's hat-trick for this category is the Charger 3.5L at a PSD of 142.1 feet. The Chevrolet Impala 9C1 3.9L took fourth at a PSD of 143.2 feet with the Ford Police Interceptor 3.27 4.6L at a PSD of 143.6 feet.
The Ford F-150 Super crew came out ahead in the Special Service group with a PSD of 147.3 feet. The Chevrolet Suburban 3/4 ton, Ford Explorer and Expedition all stopped within a single foot of each other at 156.4, 156.5 and 156.8 respectively.
The Harley-Davidson and BMW motorcycles, however, had a large difference between the two manufactures. The BMW R1200RTP took first place in the motorcycle group, but second overall, with a PSD of 139 feet. The Harley-Davidson Road King and Electra Glide, while not last overall, had a PSD of 171.4 and 173.3 respectively.
See Table 5 on Page 54 and Table 6 on Page 55 for additional vehicle braking results.
Acceleration and top speed
The vehicle acceleration test objective was to determine the ability of each test vehicle to accelerate from a standing start to 100 mph with data checkpoints at various speeds. The vehicle top speed test objective is to determine the actual top speed attainable within a distance of 14 miles from a standing start. After the fourth acceleration run, the vehicle continued to accelerate to the top speed attainable within the 14 miles provided at the DaimlerChrysler Proving Grounds.
Using the Datron optical sensor, each vehicle was driven through four acceleration sequences: two northbound and two southbound to allow for wind direction. The four resulting times for each target speed were averaged, with and reported.
Accelerating to every speed acceleration-mark quickest is the Dodge Charger 5.7L reaching 60 mph at 6.24 seconds and 100 mph at 15.29 seconds. The Charger 5.7L also took the top speed mark at a 148 mph — the exact top speed the Charger took the top speed category with in the 2007 testing. The Chevrolet Impala 9C1 3.9L and its E85 counterpart got to 60 mph in a 0.04 second difference and 100 mph in a 0.07 second difference with top speeds of 142 and 141 mph respectively. With a considerable top speed drop to 132 mph in the fourth and fifth positions, the Dodge Charger 3.5L and Magnum 3.5L kept a close acceleration pace with each other throughout. Here the Charger met 60 mph at 8.68 seconds with the Magnum at 8.81. However, their difference grew slightly as the speed increased — the Charger reaching 100 mph in 23.15 seconds and the Magnum in 23.96. The remaining top speeds of the general service vehicles ranged from 131 to 120 mph.
Only two of the special service vehicles broke the 100 mph mark, both from Ford. The Ford Expedition reached 60 mph at 8.81 seconds — the same time as the Dodge Magnum general service vehicle — with a top speed of 105 mph. Even though the Ford Explorer met every acceleration mark up to 100 mph quicker than the Expedition, the Explorer's top speed was only 1 mph less than the Expedition.
The BMW R1200RTP came out on top in the Motorcycle group at a 130.9 mph top speed, meeting 100 mph from 60 mph in 6 seconds. The Harley-Davidson Road King and Electra Glide vehicles met their top speeds relatively closely at 109.1 mph and 106.2 mph, respectively. However, the Electra Glide's acceleration dropped dramatically from the Road King in the 90 mph to 100 mph range. It took the Electra Glide about 11 seconds longer than the Road King to reach 100 mph.
See Table 2 and Table 3 on Page 53 for additional vehicle acceleration and top speed results.
As winning isn't the ultimate goal in the Police Vehicle Evaluation and Purchasing Program, vehicles with the best times, speed and ratings aren't the only factors in choosing the correct vehicle for an agency's mission. Following the road tests, the program also includes a ergonomics analysis, focusing on issues such as console and equipment placement in relation with drivers and passengers. The program supplies law enforcement with its objective evaluation to enable those interested the ability with to examine and compare data side-by-side.
Editor's Note: All test results are preliminary and are subject to change upon confirmation of data with the Michigan State Police. Additional information on the 2008 and previous year's Police Vehicle Evaluation and Purchasing Program can be found online at www.michigan.gov/msp.