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Los Angeles Sheriff Tests 2012 Police Vehicles

Written by John Bellah

Each fall, the Los Angeles County Sheriff’s Department 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, which began testing police vehicles in 1956. The current testing program involves EVOC instructors from both agencies as test drivers.

For more than 50 years, the vehicle testing has been held at the Los Angeles County Fairgrounds, home of drag racing’s Winternationals in Pomona. In fact, this famous drag strip is still used for acceleration testing, and the massive parking lot is still used for the city pursuit course.

Again this year, some of the high-speed testing was held at the Auto Club Raceway in Fontana. The site of the former Ontario Motor Speedway, this is the location of events like the NASCAR Sprint Cup Series, Pepsi 500 and Auto Club 500 races. Since the LASD vehicle testing protocol emphasizes braking and handling characteristics, one of the interior tracks is used, rather than the high-speed banked oval track.

Fontana’s interior road course is remarkably similar to the old Pomona road course. While both courses are asphalt-paved and have flat curves, the new course contains some 90-degree, “S” and hairpin curves – 13 turns in all. However, at 1.47-miles, the Fontana is slightly shorter than the old 1.57-mile Pomona course. Test protocols remained similar on the new track.

Sedan, Crossover and SUV Test Vehicles

Ford offers two new and different vehicles to replace the discontinued Ford CVPI. One is the Sedan Police Interceptor based on the Taurus and the other the Utility Police Interceptor based on the Explorer crossover. The Sedan PI is available with the choice of the 280 hp, 3.5L V6, or the optional twin-turbocharged, 365 hp, 3.5L EcoBoost V6. The Sedan PI comes standard as an All-Wheel Drive, while Front-Wheel Drive is available as a delete-for-credit option with the non-turbo engine. The twin-turbo engine requires AWD.

Dodge submitted the Charger Pursuit in both the 292 hp, 3.6L Pentastar V6 and 370 hp, 5.7L HEMI® V8. Both powertrains versions were tested with both the standard 2.65:1 rear gear ratio and the optional performance axles: 3.06 ratio (V8) or 3.07 ratio (V6).

Chevrolet provided their large Caprice PPV. New for 2012 is a 301hp, 3.6L High Feature V6. Sourced from Camaro and Cadillac, this is the same DOHC, variable valve timing engine used in the Impala 9C1. On the Caprice, a 355 hp, 6.0L V8 is available as a no-cost option. The Caprice is Rear-Wheel Drive.

The 2012 Chevrolet Impala 9C1 is powered by a slightly smaller but much more powerful engine compared to last year. The 3.6L High Feature V6 makes 302 hp – a more than 70 hp increase. A new 6-speed automatic replaces last year’s 4-speed. The Impala uses a FWD drivetrain.

The Ford Utility PI is powered by a 300 hp, 3.7L V6. This crossover is built off the same basic platform as the Sedan PI, and shares many powertrain, driveline and chassis components. Like the Sedan PI, the Utility PI also comes standard as AWD with FWD as an option. Chevrolet’s large SUV, the Tahoe PPV, rounded out the vehicle testing. This SUV uses the 320 hp, 5.3L V8 and is strictly a RWD vehicle.

Preliminary Handling Test

All these vehicles are pursuit-certified, police package vehicles, identified as such by their respective manufacturers. The first test is the Preliminary Handling Test at Fontana. This is a high-speed course. Speeds in excess of 100 mph at the end of the straight-aways are common. All four drivers, two from LAPD and two from LASD, drive eight laps – for a total of 32 laps. The crossovers and SUVs are tested with 400 pounds of ballast in the cargo area to simulate how the vehicle will perform in the field with a simulated load of police gear. The sedans do not have ballast added.

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. This year the Charger 5.7L V8 with the 3.06 rear axle was disqualified due to brake failure during the last eight laps. The LASD testing protocol does not allow a re-test. Chrysler engineers indicated the failure was a specific issue with that particular test vehicle and not the overall design of the Charger Pursuit brake system.

The stand-alone fastest police vehicle on the Preliminary Handling Test was the twin-turbo Sedan PI. The new Ford was followed by the Charger Pursuit 5.7L and then the Caprice 6.0L. These three sedans with their base V6 engine and the Impala 9C1 V6 were clustered close behind, all within two seconds of one another. The Ford Utility PI with its standard AWD and V6 drivetrain was 1.5 seconds ahead of the V8-powered, RWD Tahoe.

Brake Testing

Immediately after completing the Preliminary Handling Test, the brakes are tested under simulated real-world police operating conditions with hot brakes and tires. This duplicates conditions after an emergency run or a vehicular pursuit. This is the most severe brake test performed by the police community. After a brake warm-up procedure, the vehicle is then accelerated to 60 mph and the brakes applied to simulate a “panic-stop” with ABS activation.

The best braking performance came from the Caprice PPV, Ford Sedan PI then Charger Pursuit – in each case, powered by the baseline V6 engine. Among the more powerful drivetrains, it was Caprice, then Charger, then Ford Sedan PI. All the sedans stopped within 12 feet of one another – about a half car-length. The majority of sedans outbraked the crossovers / SUVs, and the Utility PI crossover outbraked the Tahoe SUV by 8 feet.

Acceleration

The acceleration times to various speeds up to 100 mph are recorded. So are the one-fourth-mile Elapsed Time and Trap Speeds. In nearly every case, the vehicle with the quickest zero-to-60 mph time also has the quickest one-fourth-mile time and speed. (Maximum top speeds are not attempted or measured.)

The best E.T. came from the twin-turbo Sedan PI 3.5L EcoBoost V6 followed by the Caprice PPV 6.0L V8 and the Charger Pursuit 5.7L V8. These all ran in the six-second, zero-to-60 mph bracket. The V6 versions of these sedans generally ran in the eight-second bracket, as did the Ford Utility PI with the 3.7L V6. The Tahoe was about a second slower to 60 mph.

Fuel Mileage

The Fuel Efficiency Test simulates real-world conditions over a 100-mile course. Each vehicle is driven through the course four times with two different drivers. The course is divided equally with urban, suburban and freeway driving conditions, and takes place during peak (rush-hour) traffic conditions. Headlights and air conditioning are turned on and the transmissions are placed in the default “Drive” position.

The vehicles are neither driven gently nor driven aggressively. 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.

The Charger Pursuit with the 3.6L V6 and 2.65 axle ratio achieved the stand-alone best fuel mileage: 19.6 mpg! The rest of the sedans with baseline V6 engines averaged in the high-17s mpg. The twin-turbo Sedan PI EcoBoost and the Charger 5.7L V8 got high-16s mpg. The Caprice V8 and the Utility PI V6 were in the mid-14s mpg. The Tahoe checked in with a 12.2 mpg average.

Each deputy fills out a checklist rating their impression of each individual vehicle. The evaluations are conducted separately and the ratings are averaged to minimize any individual prejudices for or against any of the vehicles. Vehicles are evaluated for general suitability and efficiency as a patrol vehicle, or other specific functions that the LASD may require. The Los Angeles County Sheriff’s Department does not recommend any specific vehicle or tire. Their test results are published annually and are available on their website.

John Bellah is the technical editor for Police Fleet Manager and is a member of SAE International. Bellah is a retired Southern California police officer with over 32 years of service. He may be reached at pfmteched@yahoo.com.

Published in Police Fleet Manager, Mar/Apr 2012

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