Each year, the Los Angeles County Sheriff’s Department (LASD)
conducts performance and fuel economy tests on police package vehicles. The current LASD program dates back to 1974 when they took it over from the Los Angeles Police Department (LAPD). The LAPD had begun testing police vehicles in 1956! The current testing actually involves both agencies. Each department supplies EVOC instructors to evaluate the vehicles.
In comparison with the annual vehicle tests performed by the Michigan State Police, the Los Angeles Sheriff testing program places less emphasis on top speeds and more emphasis on handling, braking and mechanical reliability.
The LASD Vehicle Tests for 2010 police vehicles were a milestone event. For more than 50 years, the vehicle testing had been held at the Los Angeles County Fairgrounds, also known as Fairplex. This is in Pomona, home of drag racing’s Winternationals. In fact, the famous drag strip was used for some of the police vehicle tests. The road course was a flat (no banks, no hills, no valleys), 1.57-mile asphalt course with several turns and two long straights, allowing up to 100 mph speeds at the end of the straight.
This year’s testing was held at the Auto Club Raceway in Fontana. This is a fairly new track, located on the site of the former Ontario Motor Speedway. This track hosts events such as the NASCAR Sprint Cup Series, Pepsi 500 and Auto Club 500 races. Formerly called California Speedway, this is a modern, 2-mile, high-speed banked oval.
Because the LASD vehicle testing protocol emphasizes braking and handling characteristics, rather than top speeds, the banked oval track was not used. Inside the speedway are additional tracks for sports cars, drag racing, go-karts, motorcycles and the “Interior Circuit” track. For the LASD vehicle evaluation, the Interior Circuit track was used. The Automobile Club of Southern California also uses this track for in-house testing and evaluation of retail vehicles.
The Interior Circuit road course at Fontana is remarkably similar to the old Pomona road course. Both are flat and asphalt-paved. The new course contains some 90-degree, “S,” and hairpin curves—13 turns in all. However, at 1.47 miles, the Fontana course is slightly shorter than the old 1.57-mile Pomona course. Test protocols remained similar on the new track, and top speeds obtained were similar to those obtained on the old course.
The LASD and LAPD test drivers commented that the new track is a fun course to run; however, it is even more abusive to brakes and tires than the old course. Top speeds at the end of the straight stretches on both tracks are almost identical, and so are the overall lap times. Average speeds at Fontana, however, were about 5 mph slower than laps at Pomona.
Test drivers commented that the asphalt-paved Auto Club Raceway is more consistent; however, the new course with banked turns is far more abusive to the vehicles, especially tires and brakes. Test drivers noted that handling and braking deteriorated as the vehicles progressed further through the 32-lap Preliminary Handling Tests. They deduced that as the tires heated up, their grip deteriorated. After the test runs were concluded, it was evident that the tires had taken a considerable amount of abuse, as indicated by tread wear at the end of the course.
The police package vehicles tested this year were the Ford CVPI 4.6L V8 in both 3.27 rear gear and optional 3.55 rear gear; the Dodge Charger in both 3.5L V6 and 5.7L V8; the Chevrolet Impala 3.9L V6 in both gasoline and E85 versions; and the Chevrolet Tahoe 5.3L V8 in both gasoline and E85 versions. Only police package vehicles were tested—not special service vehicles. Preliminary Handling Test
All police package (pursuit-certified) vehicles must undergo the Preliminary Handling Test. Each vehicle is driven eight laps by a test driver. Two EVOC instructors from the LASD and four EVOC instructors from the LAPD are used for each vehicle for a total of 32 laps. This is the higher speed course, with average speeds between 58 and 64 mph. The other test, the Pursuit Course that simulates city streets, has average speeds between 40 and 43 mph.
Speeds and times were measured by utilizing a GPS-based “V-BOX Datalogger” which is mounted in the vehicle. Both the fastest and slowest laps are automatically eliminated, and the remaining six laps are averaged. Each driver also subjectively and independently evaluates each vehicle at the end of this phase. Vehicles that are rated as “unacceptable” are disqualified and are not allowed to participate in further testing. While some vehicles have been disqualified in the past at this stage in the testing, all the vehicles passed this year.
The average speeds of the pursuit-certified vehicles on the new Fontana high-speed course were a bit slower than the old Pomona high-speed course. The average lap speed at Fontana was 61 mph compared to an average lap speed at Pomona of 66 mph.
The stand-alone fastest police vehicle on the Preliminary Handling Test was the 5.7L Charger. The 3.5L Charger and the 3.55 gear Ford CVPI were in a second place group, followed by the 3.27 gear Ford CVPI, then the Impala and then the Tahoe. Slightly more than 7 seconds separated the fastest and slowest vehicles on an 85-second course, which is a big difference.
Immediately after completing the Preliminary Handling Test, the brakes are tested. This simulates actual police operating conditions with hot brakes and tires, duplicating conditions after an emergency run or a vehicular pursuit situation. This also makes this brake test the hardest, most severe brake test performed by the police community. All of the brake testing was conducted in the same area of track surface, thus maintaining the same coefficient of friction.
The test vehicle is accelerated up to a speed of 80 mph, and the brakes are applied to maintain a deceleration rate of 22 fps (squared) without ABS activation. This is repeated three additional times. The vehicle is allowed to sit stationary for 5 minutes. The vehicle is then accelerated to a speed of 60 mph and is decelerated at a maximum rate, just short of ABS activation. After a 2-minute heat-soak period, the procedure is repeated. The vehicle is then accelerated to 60 mph and stopped to simulate a “panic-stop” with ABS activation.
The police sedan with the best brakes this year was the Impala 3.9L V6 with a 161-foot average stopping distance from 60 mph. The 5.7L V8 Charger’s average stopping distance was half a car-length longer at 172 feet, followed by the two Ford CVPIs, the 3.5L V6 Charger and, at many car-lengths longer, the Tahoe.
Acceleration times to various speeds are measured, as is 1/4-mile acceleration, but maximum top speeds are not attempted or measured. The police vehicle with the fastest acceleration was the 5.7L V8 Dodge Charger with a 0 to 60 mph time of 5.9 seconds. The HEMI® Charger runs the 1/4 mile in 14.4 seconds, with a speed through the traps of 100.5 mph.
No other police vehicle is even close to the 5.7L V8 Charger. All the other police vehicles have essentially the same acceleration as each other. They all hit 60 mph in the mid 8-second range and run the 1/4 mile in the mid 16- to low 17-second range.
The final test of pursuit vehicles is the Pursuit Course. This is limited to vehicles that are rated as Police Package (pursuit-certified) by the vehicle’s manufacturers. This is a 2.16-mile course that simulates a pursuit situation within an urban environment, consisting of a maze of twisting right- and left-hand turns along with obstacles littering the roadway.
Two test drivers are used to evaluate each vehicle, and times are recorded. Each driver completes two laps around this course. The vehicle must complete the two-lap course in less than a combined time of 4 minutes, 45 seconds, which all of them did.
As in the Preliminary Handling Course, the fastest vehicle around the Pursuit Course was the 5.7L V8 Charger, and the 3.5L V6 Charger was second fastest. On the tighter Pursuit Course, the Impala 3.9L now performed equal to or better than the 3.27 gear and 3.55 gear (respectively) Ford CVPIs. The Tahoe was well behind the sedans.
Ergonomics, Gas Mileage
The Fuel Efficiency Test simulates real-world conditions and is conducted over a 100-mile course. The protocol uses patrol deputies in full uniform to drive each vehicle. Each vehicle is driven through the course four times with different drivers during peak (rush-hour) traffic conditions. The course is divided equally among urban, suburban and freeway driving conditions.
Standard E10 pump gasoline is used, even on E85 compatible vehicles. E85 fuel economy is not measured. Headlights and air conditioning are turned on, and the transmissions are placed in the default “Overdrive” position. The vehicles are driven in a normal manner, i.e., they are neither driven gently, nor driven for maximum performance.
The fuel mileage obtained from each run is then averaged. By definition, this test simulates the mileage that a detective or administrative vehicle would obtain. Experience shows that a marked patrol unit would obtain about 60 to 70 percent of these mileage figures.
Each deputy fills out a checklist rating his impression of each individual vehicle. The evaluations are conducted separately, and the ratings are averaged to minimize any individual prejudices either for or against any of the vehicles. Vehicles are evaluated for general suitability and efficiency as a patrol vehicle, or for other specific functions that the LASD may require.
The police sedan with the best gas mileage under these test conditions was the Chevrolet Impala with a 20.9 mpg average. Surprisingly, the 5.7L V8 Charger was the second most economical sedan! Chrysler Fleet has been saying this; the EPA figures reflect it. And now the Los Angeles County Sheriff’s Department has independently verified it!
At 19.1 mpg, the HEMI Charger is more fuel efficient than the 3.5L V6 Charger and is clearly more fuel efficient than either of the Ford CVPIs. The Tahoe 5.3L V8, even with the new 6-speed trans, gave the lowest mileage readings at 15.3 mpg.
Mechanics who service the department also evaluate each vehicle for ease of routine maintenance and service, as well as for ease of repair of various vehicle components. Finally, the ease of installation of communications equipment (two-way radios and Mobile Data Computers) is rated by technicians from the LASD Communications and Fleet Management Bureau. The radiated output of this equipment must not interfere with the operation or performance of the vehicle, nor may the vehicle cause excessive radio interference.
All of the 2010 vehicles submitted successfully passed all of the test phases. While the Los Angeles County Sheriff’s Department does not recommend any specific vehicle or tire, its test results are published annually. For further information on the program or copies of the complete report, contact: Los Angeles County Sheriff’s Department, Communications and Fleet Management Bureau, 1104 N. Eastern Avenue Door #50, Los Angeles, California 90063, phone (323) 267-2511.
John Bellah is the technical editor of Police Fleet Manager and a retired corporal with the California State University, Long Beach Police. He may be reached via e-mail at firstname.lastname@example.org.
Preliminary Handling Test
(1.46-mile, high-speed course)
Vehicle Lap Time
Dodge Charger 5.7L V8 1:22.42 minutes
Dodge Charger 3.5L V6 1:25.03 minutes
Ford CVPI 4.6L V8 (3.55 gear) 1:25.25 minutes
Ford CVPI 4.6L V8 (3.27 gear) 1:26.37 minutes
Chevrolet Impala 3.9L V6 1:27.03 minutes
Chevrolet Tahoe 5.3L V8 1:28.40 minutes
Vehicle 0-60 mph 1/4 Mile Time and Speed
Dodge Charger 5.7L V8 5.9 seconds 14.4 sec @ 100.5 mph
Ford CVPI 4.6L V8 (3.55) 8.4 seconds 16.4 sec @ 86.9 mph
Ford CVPI 4.6L V8 (3.27) 8.5 seconds 16.5 sec @ 87.7 mph
Dodge Charger 3.5L V6 8.5 seconds 16.6 sec @ 87.4 mph
Chevrolet Impala 3.9L V6 8.6 seconds 16.5 sec @ 87.7 mph
Chevrolet Tahoe 5.3L V8 8.8 seconds 17.1 sec @ 85.4 mph
(from 60 mph)
Vehicle Stopping Distance
Chevrolet Impala 161.5 feet
Dodge Charger 5.7L V8 172.4 feet
Ford CVPI (3.27) 176.3 feet
Ford CVPI (3.55) 176.5 feet
Dodge Charger 3.5L V6 178.2 feet
Chevrolet Tahoe 192.4 feet
(2.16-mile city street simulation)
Vehicle Combined Lap Times
Dodge Charger 5.7L V8 2:58.35 minutes
Dodge Charger 3.5L V6 3:00.84 minutes
Chevrolet Impala 3.9L V6 3:02.00 minutes
Ford CVPI 4.6L V8 (3.27) 3:02.24 minutes
Ford CVPI 4.6L V8 (3.55) 3:09.47 minutes
Chevrolet Tahoe 5.3L V8 3:10.40 minutes
Fuel Mileage Figures
(100-mile test loop)
Vehicle EPA City/Highway LASD Mileage
Chevrolet Impala 3.9L V6 17/24 20.9 mpg
Dodge Charger 5.7L V8 15/23 19.1 mpg
Dodge Charger 3.5L V6 16/25 18.6 mpg
Ford CVPI 4.6L V8 (3.55) 14/21 17.6 mpg
Ford CVPI 4.6L V8 (3.27) 14/21 15.8 mpg
Chevrolet Tahoe 5.3L V8 14/19 15.3 mpg