I hate to say it, but it has been a long misconception about police cruisers.
They do NOT have special engines or trannys. They have more heavy duty parts than their publicly sold counterparts. Like a higher output alternator, heavy duty cooling, larger brakes,oil cooler and reinforced floor pans. Most gear ratios are the same that are available to anyone and the cars are sometimes SLOWER than a showroom stock public version due to the increased weight. Some are available with the speed limiter removed though, and that makes them pretty quick. But, no high HP motors out there. Now, the new Chrysler 300 is supposed to have a Police Interceptor package in the works......340 HP Rear Wheel drive.....I wouldn't run. :headshake