Each year, the Los Angeles County Sheriff's Department pushes the new crop of patrol vehicles to their limit at a California speedway, as part of an annual performance and safety evaluation.

This year, one vehicle reached its limit early in the day, when a driver coasted the vehicle into the pit area after reached speeds exceeding 120 mph during an acceleration evaluation. Four officers had driven it for 32 laps at the Auto Club Speedway in Fontana.

The vehicle's braking would be tested next, but first the tempterature on the rotor needed to be measured. Using a non-contact infrared thermometer, evaluator Douglas Barnhart picked up a reading in excess of 1,000 degrees on the rotor surface. Not quite hot enough to burst into flames, but close.

Surprisingly enough, the vehicle performed fairly well during the braking tests, Barnhart said.

At Barnhart's Los Angeles Police Department, vehicles involved in high-speed pursuits are taken off the street and immediately inspected by mechanics for any safety hazards.

"We have a standing practice that you'll drive to the station," Barnhart said. "The rapid heat up and cool down could exacerbate a crack in the rotor."

Each year, police fleet manufacturers provide test vehicles to the LASD to test. During the Oct. 22 testing day, drivers from various agencies and the department's Emergency Vehicle Opearating Center (EVOC) driving unit evaluated the vehicles for high-speed performance, braking, ergonomics, ease of maintenance and driving dynamics.

Each driver fills out an evaluation report to rate each vehicle on a 1-10 scale for steering, body lean, bounce, brake fade, brake pull and ABS operation. Drivers make written notes on brakes, cornering and handling, transmission (shifting points), engine and other items.

This year, the sheriff's driving unit tested nine vehicles, including the Ford CVPI (3.5-liter), pair of Dodge Chargers (V-6 and V-8) and Chevrolet Impala patrol cars; the pursuit-rated Chevrolet Tahoe SUV; and Harley-Davidson Electra Glide, Honda ST1300, and BMW R1200 and G650 motorcycles.

Drivers took turns running the vehicles around the speedway track for eight laps each. They then switched turns, providing notes to the next driver abut the vehicle's performance.

This year, a sheriff's spokesman said the unit would release data on Honda's ST1300 motorcycle, a relative newcomer to the police motorcycle market that has grown in popularity with West Coast departments who like the bike's quickness and agility for open-road traffic enforcement.

Rumors of a high-speed wobble on the bike don't appear to be founded, according to Sgt. John Steele, a sheriff's motor patrol deputy who took the bike up to 115 mph on testing day.

"I have not seen a high-speed wobble on that bike," Steel said on testing day. "We've not experienced it."

The BMW RT1200 RT-P has also become a popular choice due to its performance features and ability to pace a potential speeding violater with the push of a single button. The speed of a vehicle can be logged into the bike's computer and will display on a screen on the bike, allowing officers to educate skeptical speeders.

The vehicle testing day also offered a tease of the future with the appearance of several new patrol vehicles expected to make their appearance on the track in the coming years.

Carbon Motors brought its clean-diesel E7 patrol car and General Motors showed off the Chevrolet Caprice that was announced at the International Association of Chiefs of Police trade show in Denver earlier this month.

The Caprice will be available for the 2011 model year and the E7 will be produced in 2012. Also, Ford is phasing out the "Crown Vic" CVPI — 2011 will be its  final production year — and could develop a patrol version of its Taurus sedan. The company has not announced formal plans.

If those cars are provided to EVOC, they'll be tested to their limit, said Sgt. Bob Killeen of the sheriff's fleet management unit.

"We test everything the manufacturers send us," Killeen said. "We're providing information to law enforcement agencies across the country."

Related:

Chevrolet Unveils 2011 Caprice Patrol Vehicle at IACP

Michigan State Police To Test 2010 Patrol Vehicles

2009 Police Motorcycles (photo gallery)