Last week, while in hot pursuit of a runaway vehicle on New South Wales' Pacific Highway, one of Australia’s most expensive police cars erupted into flames when... the driver parked it in some long grass.
The highway patrol car—a turbo diesel BMW 530d—was chasing a teen driver near Tweed Heads, the ABC reports, and pulled over on the roadside after a spike strip punctured the fleeing vehicle’s tyres. Moments later, the police car was ablaze. Accounting for all the equipment inside—including an in-car video system, number plate-reading technology, and breathalysers—it was worth about $200,000.
"I looked over and a fire had developed under the police car and literally within seconds the car was in flames,” eyewitness Geoff Huxley told the ABC. "The police tried to put it out with fire extinguishers but it had taken hold. It was quite extraordinary how quickly it had taken hold."
Geoff recalled that “the fire… crept under the car, into the car that was being pursued, and it [also] went up in flames."
While the exact cause of the fire is yet to be confirmed, it’s thought that the blaze was ignited by the heat radiating out of the car’s engine which could have set the grass alight. Motoring writer Toby Hagan told the ABC that something called a “diesel particulate filter”—that is, a filter that captures and stores exhaust soot in order to reduce emissions from diesel cars—could be to blame.
"When that goes into its burn-off mode, it actually builds up even more heat and therefore potentially increases that risk [of a fire],” he said. "Most modern turbo diesels have a particulate filter and to do it, it builds quite a bit of heat and what you will find is with four-wheel drives, quite regularly, the recommendations are not to park in the grass."
"If the police have actually parked on dry grass and it is the exhaust that's caused the issue, clearly there needs to be some training here," he added.