Title: Ford 300 HP Police Interceptor

By L&O Staff

One of the best things ever to happen to the Ford Police Interceptor rolled into the parking lot at Grattan Raceway without fanfare-it wasn’t even a police car. But it was one of the highest performing full size sedans since the Chevrolet Caprice with the 5.7 LT-1 engine: the 2003 Mercury Marauder.

No longer a concept car, the Marauder is scheduled for production release in April 2002. What makes this monochromatic Grand Marquis with big tires so special is the power plant: a 4.6L DOHC V-8 rated at 300 HP. The Police Interceptor uses a 4.6L SOHC V-8 with 235 HP.

For the first time in a decade, Ford Fleet acknowledged it was seriously considering a new police engine. Ford has steadily increased power from its 4.6 SOHC engine since its 1992 introduction. However, since the demise of the 260 HP Caprice in 1996, police officials have continued to request better acceleration from the full size Ford. The early emphasis was on the 5.4L SOHC engine, which has more torque for bottom end responsiveness than the 4.6L SOHC V-8. The 5.4L engine, however, will not fit in the Crown Victoria due to interference from the windshield wiper assembly.

The 4.6L DOHC engine from the Mustang Cobra and Lincoln, however, will fit in the Crown Victoria. Higher engine costs, emissions certifications, and other engineering and development costs made it prohibitive to put a Cobra engine in a Police Interceptor for just the 4,000 units per year Ford Fleet thinks it can sell.

Enter the retail Mercury Marauder, an Impala SS type of performance sedan based on the Grand Marquis, and developed for the lucrative retail market. While the Marauder engine has 28% more horsepower than the Police Interceptor, it only has nine percent more torque. The performance change will happen at the top end, where the state police and highway patrol want it, not the bottom end. With 300 HP, the 4.6L DOHC V-8 has far more horsepower than the 260 HP 5.4L SOHC V-8, and rivals the 310 HP 6.8L SOHC V-10. It still has less torque than either, which means the performance from the DOHC engine comes at the mid and top of the rpm range, not at the bottom of the range.

The 300 HP Marauder comes with a 3.55 rear gear and is limited to 120 mph. The police version will use the 3.27 rear gears. A Police Interceptor with the Marauder engine and Police Interceptor gearing is estimated to reach 0-60 mph in 7.5 seconds and have a top speed of 140 mph. The three year average of the LT-1 Caprice was 8.2 seconds and 138 mph respectively. The five year average for the 4.6L Crown Victoria is acceleration to 60 mph is 8.7 seconds, with a range from 8.4 to 9.0 seconds.

For a number of years, Ford has had the goal of a zero to 60 mph time of eight seconds and a top speed of 130 mph for its Police Interceptor. The top speed has been achieved. However, the zero to 60 mph and zero to 100 mph acceleration goals have been elusive with the 4.6L SOHC V-8. Since its 1998 remodeling, the Police Crown Victoria has had an increase from 215 to 235 HP, used two different rear axles and two different torque converters, among major changes.

Driveshaft harmonics limit the rear gear ratio to 3.27. The Crown with quicker accelerating 3.55 gears are limited to 119 mph. The composite driveshaft, which dampened the harmful harmonic vibrations and allowed higher top speeds with the 3.55 gears, is no longer available. The 3.27 gears allow top speeds up to 129 mph but at a slower acceleration.

Each platform has a harmonic resonance that prevents accelerating above a certain speed. These are the harmonic vibrations that resulted from premature transmission oil seal failures and fluid leaks on Crowns in the late 1990’s. The result was to limit those 3.55 geared cars to 119 mph and use a composite driveshaft.

Each platform and drivetrain is different. For example, a 5.7L Caprice could use 3.42 gears and run well over 140 mph without encountering such harmonics. The Crown Victoria platform is different.

The in service maintenance on the 4.6L DOHC engine, proven in muscle and luxury cars, should be similar to the 4.6L SOHC engine currently used in the Police Interceptor. The initial cost of a Crown Victoria with the DOHC engine will be higher and the higher performance engine will not be as fuel efficient as the SOHC engine.

The use of the 4.6L DOHC V-8 in the Police Interceptor is by no means certain. However, 80% of the development to place the engine in the police car is already done in installing the engine in the retail Marauder. To express interest in this powertrain, Tony Gratson, Ford’s new national government sales manager, can be reached at (313) 390-0791 or via e-mail at tgratson@ford.com.        

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