N40GL
01-27-2005, 09:55 AM
{I thought this might make interesting reading. From Police Fleet Manager's most recent issue}
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 has been performed on the 2.0-mile road course at Grattan Raceway near Grand Rapids, MI.
The 2005 police package vehicles tested were the 4.6L V-8 Ford Crown Victoria Police Interceptor (CVPI) with both 3.27:1 and 3.55:1 rear axle ratios, the 3.8L V-6 Chevrolet Impala and the 5.3L V-8 Chevrolet Tahoe 2WD with both gasoline and E85 fuel.
The 2005 special service package vehicles tested were the 4.6L V-8 Ford Explorer 4X4, the 5.4L V-8 Ford Expedition 4X4, the 5.3L V-8 Chevrolet Tahoe 4X4, the 3.5L V-6 Dodge Magnum, and 6.6L V-8 Chevrolet Silverado 4X4 pickup.
Acceleration
The Ford CVPI with the 3.55 ratio rear axle was the quickest police or special service sedan to 60 mph, 80 mph and 100 mph, which are the three MSP focus speeds. While the vehicle must meet certain minimums at all three of these speeds, the zero to 100 mph times determine the winner of this test phase.
The police sedan with the second quickest acceleration was the 3.27-geared Ford CVPI. The 3.27 ratio is less than 0.3 seconds slower to 60 mph than the 3.55 car, and within 0.4 seconds of the 100 mph time. The Ford CVPI was an average of two seconds faster to 100 mph than the special service Dodge Magnum and police package Chevrolet Impala.
The 250 hp, 3.55-geared Ford CVPI really is comparable to the legendary Chevrolet LT-1 Caprice in terms of acceleration. The average acceleration to 60 mph for the 5.7L Caprice was 8.2 seconds. The 3.55 geared Ford CVPI hits 60 mph in 8.15 seconds. The zero to 100 mph times are surprisingly close. The Caprice hit 100 mph in 21.9 seconds, while the 3.55-geared CVPI reached it in 22.9 seconds.
New for 2005 is the pursuit-rated, 2WD Tahoe SUV. Among the SUVs, the police package Tahoes, one powered by gasoline, one powered by E85, were the hot rods. And not just fast for an SUV, but fast outright. Each hit 60 mph in 8.2 seconds, like the 3.55 geared Ford CVPI and old Caprice LT-1. Each hit 100 mph in the 23 second bracket, splitting the difference between the 3.55 CVPI and the 3.27 CVPI.
The Ford Explorer and Expedition, and the Chevrolet 4X4 Tahoe reached 60 mph in the 9 second bracket. Honorable Mention goes to the Chevrolet Silverado with its turbo diesel V-8. It reached 60 mph in 11 seconds and 100 mph in 28 seconds.
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. For one reason or another, all police and special service vehicles are electronically speed limited but not all vehicles actually reach that pre-set, limited speed. All vehicles are run without speed-robbing spotlights and lightbars.
The police or special service sedan with the highest top speed is the 3.27 ratio Ford CVPI with a run at 128 mph, speed-limited to 129 mph. Second, was the Impala, which was speed-limited to 123 mph. The 3.55-geared CVPI is speed limited to 119 mph to prevent unwanted driveshaft harmonics. The special service Dodge Magnum reached 117 mph.
The police package 2WD Tahoe has a much higher electronic speed limit than the special service 4WD Tahoe. The police-spec versions reach between 124 and 125 mph. All of the special service SUVs are all severely speed limited. The 4WD Tahoe and the Expedition all shut off around 100 mph. The Explorer reached 107 mph. The Silverado, speed limited to 99 mph, actually hit 100 mph, but just once.
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 90 mph and 60 mph stops are repeated. The best 10 out of 12 stops from 60 mph are averaged for the final deceleration rate. This then is converted to a projected stopping distance from 60 mph.
The MSP has established a maximum stopping distance for their large patrol sedans, both RWD (Ford CVPI) and FWD (Impala). The standard is roughly the same at 149.7 feet and 149.1 feet, respectively.
For 2005, for the fifth time in the six years since its release, the Chevrolet Impala turned in the best braking performance of any police sedan. Using Camaro-sized brakes, the police Impala stopped like a Camaro in just 136 feet from 60 mph after a brutal brake warm-up. The special service Magnum was next with a 143 foot stop.
The 2005 CVPI stopped in an average of 147 feet. The stopping distances near, but under, the MSP limit are attributed to the 2003 suspension change, which positioned the front caliper and brake assembly deeper inside the deeply offset wheel and out of the cool, outside airflow. Moving the caliper assembly farther inside the wheel allowed the suspension to be set more outboard, which greatly improved the handling on the 2003 models.
This change forced Ford to deal with brake cooling. Among the other changes, like pad material, is the use of steel wheels with additional vent openings, a rolling change to the 2004 models produced in mid-year. In the future, expect a 17-inch wheel, like used on the Ford Crown Victoria Sport, to be introduced on the CVPI. This change will positively get the outside air inside the wheel to cool the brakes.
The MSP has established a maximum braking distance for a police/pursuit-capable SUV but does not establish maximums for special service package SUVs. As a reference only, the police SUV must stop from 60 mph in 170 feet. All the special service SUVs stopped between 142 and 153 feet! The Silverado, however, took 173 feet. Ironically, the heaviest SUV of those tested, the 5360-pound Expedition, edged out the other SUVs with the shortest stop.
Road Course
The Grattan Raceway is a two mile, 13 turn road-racing course. The road course has a 3200-foot front straightaway. By the end of the, the 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 their Precision Driving Unit.
The 3.55-geared Ford CVPI was the quickest vehicle around the road course, followed a half second later by the 3.27-geared CVPI. The Impala trailed by more than two seconds, or 10 car-lengths. The police package 2WD Tahoe was an additional two seconds behind.
The MSP does not test special service package vehicles, like the Dodge Magnum, Ford Explorer, Chevrolet Tahoe 4X4, Ford Expedition or Chevrolet Silverado on the road course. This is an emphasis that, in addition to clear and frequent written disclaimers from each manufacturer, these vehicles are not designed nor intended for high-speed or pursuit-style driving.
Ergonomics and Communications
The ergonomics and communications installation rating by the MSP involves a 27-point, subjective evaluation performed by four state troopers. They consider legroom, hip room, ease of entry and exit, along with the ease of installing communication and enforcement gear. Of the 2005 sedans, the Ford Crown Victoria was subjectively ranked the highest with 202 points. The Impala was close behind with 200 points.
This years' ergonomic evaluation continues the see-saw results between the CVPI and the Impala. One wins one year, while the other wins the next year. A four-year average may put this into a better perspective. During this time, the Impala averaged 206 "points" compared to 205 "points" for the Ford CVPI, a statistical tie.
The special service Magnum was well behind the two police package sedans with 185 points, the lowest of any police or special service vehicle. The Magnum got high marks in areas like front seat adjustability and front headroom, but low marks for dashboard access, trunk access and rear visibility.
Among the SUVs, for the fourth year in a row, the Tahoe got the highest ergonomic ratings, followed by the Expedition and then Explorer, for the third year in a row. The Silverado pickup truck checked in with 203 "points" beating all the police sedans and all of the SUVs except the Tahoe!
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 has been performed on the 2.0-mile road course at Grattan Raceway near Grand Rapids, MI.
The 2005 police package vehicles tested were the 4.6L V-8 Ford Crown Victoria Police Interceptor (CVPI) with both 3.27:1 and 3.55:1 rear axle ratios, the 3.8L V-6 Chevrolet Impala and the 5.3L V-8 Chevrolet Tahoe 2WD with both gasoline and E85 fuel.
The 2005 special service package vehicles tested were the 4.6L V-8 Ford Explorer 4X4, the 5.4L V-8 Ford Expedition 4X4, the 5.3L V-8 Chevrolet Tahoe 4X4, the 3.5L V-6 Dodge Magnum, and 6.6L V-8 Chevrolet Silverado 4X4 pickup.
Acceleration
The Ford CVPI with the 3.55 ratio rear axle was the quickest police or special service sedan to 60 mph, 80 mph and 100 mph, which are the three MSP focus speeds. While the vehicle must meet certain minimums at all three of these speeds, the zero to 100 mph times determine the winner of this test phase.
The police sedan with the second quickest acceleration was the 3.27-geared Ford CVPI. The 3.27 ratio is less than 0.3 seconds slower to 60 mph than the 3.55 car, and within 0.4 seconds of the 100 mph time. The Ford CVPI was an average of two seconds faster to 100 mph than the special service Dodge Magnum and police package Chevrolet Impala.
The 250 hp, 3.55-geared Ford CVPI really is comparable to the legendary Chevrolet LT-1 Caprice in terms of acceleration. The average acceleration to 60 mph for the 5.7L Caprice was 8.2 seconds. The 3.55 geared Ford CVPI hits 60 mph in 8.15 seconds. The zero to 100 mph times are surprisingly close. The Caprice hit 100 mph in 21.9 seconds, while the 3.55-geared CVPI reached it in 22.9 seconds.
New for 2005 is the pursuit-rated, 2WD Tahoe SUV. Among the SUVs, the police package Tahoes, one powered by gasoline, one powered by E85, were the hot rods. And not just fast for an SUV, but fast outright. Each hit 60 mph in 8.2 seconds, like the 3.55 geared Ford CVPI and old Caprice LT-1. Each hit 100 mph in the 23 second bracket, splitting the difference between the 3.55 CVPI and the 3.27 CVPI.
The Ford Explorer and Expedition, and the Chevrolet 4X4 Tahoe reached 60 mph in the 9 second bracket. Honorable Mention goes to the Chevrolet Silverado with its turbo diesel V-8. It reached 60 mph in 11 seconds and 100 mph in 28 seconds.
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. For one reason or another, all police and special service vehicles are electronically speed limited but not all vehicles actually reach that pre-set, limited speed. All vehicles are run without speed-robbing spotlights and lightbars.
The police or special service sedan with the highest top speed is the 3.27 ratio Ford CVPI with a run at 128 mph, speed-limited to 129 mph. Second, was the Impala, which was speed-limited to 123 mph. The 3.55-geared CVPI is speed limited to 119 mph to prevent unwanted driveshaft harmonics. The special service Dodge Magnum reached 117 mph.
The police package 2WD Tahoe has a much higher electronic speed limit than the special service 4WD Tahoe. The police-spec versions reach between 124 and 125 mph. All of the special service SUVs are all severely speed limited. The 4WD Tahoe and the Expedition all shut off around 100 mph. The Explorer reached 107 mph. The Silverado, speed limited to 99 mph, actually hit 100 mph, but just once.
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 90 mph and 60 mph stops are repeated. The best 10 out of 12 stops from 60 mph are averaged for the final deceleration rate. This then is converted to a projected stopping distance from 60 mph.
The MSP has established a maximum stopping distance for their large patrol sedans, both RWD (Ford CVPI) and FWD (Impala). The standard is roughly the same at 149.7 feet and 149.1 feet, respectively.
For 2005, for the fifth time in the six years since its release, the Chevrolet Impala turned in the best braking performance of any police sedan. Using Camaro-sized brakes, the police Impala stopped like a Camaro in just 136 feet from 60 mph after a brutal brake warm-up. The special service Magnum was next with a 143 foot stop.
The 2005 CVPI stopped in an average of 147 feet. The stopping distances near, but under, the MSP limit are attributed to the 2003 suspension change, which positioned the front caliper and brake assembly deeper inside the deeply offset wheel and out of the cool, outside airflow. Moving the caliper assembly farther inside the wheel allowed the suspension to be set more outboard, which greatly improved the handling on the 2003 models.
This change forced Ford to deal with brake cooling. Among the other changes, like pad material, is the use of steel wheels with additional vent openings, a rolling change to the 2004 models produced in mid-year. In the future, expect a 17-inch wheel, like used on the Ford Crown Victoria Sport, to be introduced on the CVPI. This change will positively get the outside air inside the wheel to cool the brakes.
The MSP has established a maximum braking distance for a police/pursuit-capable SUV but does not establish maximums for special service package SUVs. As a reference only, the police SUV must stop from 60 mph in 170 feet. All the special service SUVs stopped between 142 and 153 feet! The Silverado, however, took 173 feet. Ironically, the heaviest SUV of those tested, the 5360-pound Expedition, edged out the other SUVs with the shortest stop.
Road Course
The Grattan Raceway is a two mile, 13 turn road-racing course. The road course has a 3200-foot front straightaway. By the end of the, the 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 their Precision Driving Unit.
The 3.55-geared Ford CVPI was the quickest vehicle around the road course, followed a half second later by the 3.27-geared CVPI. The Impala trailed by more than two seconds, or 10 car-lengths. The police package 2WD Tahoe was an additional two seconds behind.
The MSP does not test special service package vehicles, like the Dodge Magnum, Ford Explorer, Chevrolet Tahoe 4X4, Ford Expedition or Chevrolet Silverado on the road course. This is an emphasis that, in addition to clear and frequent written disclaimers from each manufacturer, these vehicles are not designed nor intended for high-speed or pursuit-style driving.
Ergonomics and Communications
The ergonomics and communications installation rating by the MSP involves a 27-point, subjective evaluation performed by four state troopers. They consider legroom, hip room, ease of entry and exit, along with the ease of installing communication and enforcement gear. Of the 2005 sedans, the Ford Crown Victoria was subjectively ranked the highest with 202 points. The Impala was close behind with 200 points.
This years' ergonomic evaluation continues the see-saw results between the CVPI and the Impala. One wins one year, while the other wins the next year. A four-year average may put this into a better perspective. During this time, the Impala averaged 206 "points" compared to 205 "points" for the Ford CVPI, a statistical tie.
The special service Magnum was well behind the two police package sedans with 185 points, the lowest of any police or special service vehicle. The Magnum got high marks in areas like front seat adjustability and front headroom, but low marks for dashboard access, trunk access and rear visibility.
Among the SUVs, for the fourth year in a row, the Tahoe got the highest ergonomic ratings, followed by the Expedition and then Explorer, for the third year in a row. The Silverado pickup truck checked in with 203 "points" beating all the police sedans and all of the SUVs except the Tahoe!