Michigan test archive

1984 Michigan State Police Patrol Vehicle Test

Thirteen cars on one Saturday at the Chrysler Proving Grounds, two Mustangs, four cars scored, and a book printed before the bids were opened.

The problems, in the book’s words

The preface warns that “a number of problems were encountered which do require some explanation”, and lists them.

The Crown Victoria was re-timed. “First, the acceleration and top speed figures shown for the Ford Crown Victoria 351-VV H.O. are from a second sequence of runs for the car. During the first sequence, the car did not perform to its expected potential. After a brief mechanical check, it was determined that the timing was not set to manufacturer’s specifications. Once the timing was reset, the car was retested resulting in the acceleration and top speed figures reported.” The first runs are not printed. The retest was the last run of the day, starting at 3:58 p.m.

The LTD lost its brakes. “Second, the Ford LTD 302-EFI H.O. initially passed the acceleration, top speed, and braking tests; however, was withdrawn from further testing after completing only one-fourth of the vehicle dynamics evaluation due to brake failure, later found to have been caused by a faulty master cylinder.” Its four laps, all by Ring, are printed, but “these times should not be compared against the “average” times given for the cars that did successfully complete the test, as only one driver tested the car.” Every data page calls this engine CFI, central fuel injection.

The five-speed Mustang overheated. “Third, the Ford Mustang 302-4V H.O. (manual transmission) successfully completed its four acceleration runs but experienced serious overheating on its top speed run after attaining 129.6 mph. As a result, the car was withdrawn from further testing.” The automatic Mustang, the book adds, “did successfully complete the entire test sequence. It should be noted, however, that the car was not equipped with “police package” brakes, and the rear brakes did require adjustment at one point during the vehicle dynamics testing.”

The Reliant’s brakes would not lock. “Finally, it should be noted that the brakes on the Plymouth Reliant would not lock in the final phase of the braking evaluation and consequently failed to meet our brake specification requirement. Chrysler Corporation officials, after later checking the vehicle, indicate that the failure to lock was caused by air in the brake lines.”

All thirteen cars: acceleration and top speed

Among the scored cars the Impala was quickest to 60 (10.30 s) and the Gran Fury to 80 and 100 (19.39 and 34.43) and fastest (121.4 mph). The mid-size Ford LTD, not scored, beat all four to 60, 80 and 100 mph and on top speed: 10.29, 17.88, 29.89 and 122.6 mph. The automatic Mustang ran 118.3; the five-speed’s 129.6 was where it overheated, short of the 1983 Mustang’s 132.0. Its 7.43 seconds to 60, 20.77 to 100 and 15.90-second quarter mile at 89.00 mph were the quickest in the books held here to that point (the 1983 Mustang’s were 8.32, 22.71 and 16.68 at 86.25); the 1986 five-speed beat the first two, the 1987 car the trap speed and the 1988 car the quarter-mile time. Against the printed bar, the Celebrity took 13.90, 25.81 and 61.54 seconds and needed 5.70 miles to reach 110; the Reliant took 28.23 to 80, has no 0–100 average because one run did not reach 100 within 2 miles, and never reached 110; the two-barrel Gran Fury was outside the 80 and 100 times and never reached 110; the 302 Crown Victoria, the six-cylinder Impala and the Aries were outside all three acceleration times and never reached 110 mph. The book names none of them as eliminated; none of them is among the four scored.

See the original pages: the three summary pages in the 1984 book

The road course

The four scored cars finished within 0.43 seconds: Impala 1:29.97, Gran Fury 1:30.01, Crown Victoria 1:30.07, Diplomat 1:30.40. The automatic Mustang averaged 1:26.81, and Olson’s 1:25.99 in it was the fastest single lap of the test. That average is the fastest on the year pages held here to that point, where the best had been the 1983 Mustang’s 1:28.31, and the best by a sedan the 1981 Malibu’s 1:30.37; the Impala’s 1:29.97 is the first sedan average under 1:30 on them (from 1983 the average is of the best 12 of 16 laps; on all 16 the Impala averages 1:30.31, and the course length is not on the surviving pages). The 1986 Mustangs went quicker still. Olson was the slowest of the four drivers in every sedan and the fastest in the Mustang.

Brakes

† The Gran Fury’s first stop is printed twice: 156.6 feet on its brake sheet (p.42) and 156.5 in the summary (p.29). The book’s own rate, 25.24 ft/s² from 60.6 mph, is what 156.5 feet gives (25.24; 156.6 would give 25.22), so 156.5 is printed here as the figure of record.

The Impala stopped best, 26.38 ft/s² on average, and its first stop, 142.4 feet from 60.7 mph, was the shortest of the test and the shortest stop printed in the books held here until the 1987 Gran Fury’s 139.6. The Diplomat stopped worst, 23.36, after a 174.8-foot first stop. Every car showed no severe fade and stopped straight in its lane; only the Reliant’s brakes would not lock. Five cars were not brake-tested: the five-speed Mustang (withdrawn after its top-speed run), the two-barrel Gran Fury, the 302 Crown Victoria, the six-cylinder Impala and the Aries. Their braking rows in the summary are blank, and the book gives no reason.

Ergonomics and communications

The Crown Victoria led, first or level first on every front-seat item and with a 9.0 for its dome and map light. The Diplomat and Gran Fury columns are identical item for item. The Impala’s outside mirrors scored 1.4 and their controls 1.0; the two Chrysler cars’ door-lock switch scored 0.8. For installing equipment the Crown Victoria scored lowest on dash and engine accessibility, 5.2 and 4.0.

Fuel economy

Hardware

The Crown Victoria 351 is the “LTD Crown Victoria “S”” with the “351/5.8W H.O.” variable-venturi engine and dual exhaust; at 4,084 lb it was the heaviest car tested. The three Chrysler M-bodies, the Diplomat and both Gran Furys, used the A999 transmission, without overdrive. Three cars had Ford’s central fuel injection: the LTD, the automatic Mustang and the 302 Crown Victoria. The five-speed Mustang’s four-barrel 302, at 205 horsepower, was the most powerful engine in the test.

The scoring

The weights printed on p.50 are 30% vehicle dynamics, 20% acceleration, 10% braking rate, 20% top speed, 10% fuel consumption and 10% ergonomics and communications. The method is the weighted Z-score of the early books: each raw score is turned into a “Z”-score, “the decimal amount of standard deviations from the mean”, multiplied by the category weight, and summed into the “TOTAL WTD DEV” (Total Weighted Deviation). Higher is better. The bid adjustment was to be the total “times 5% of the median bid price of all vehicles”, added to the actual bid.

See the original page: Competitive Patrol Vehicle Evaluation

The Gran Fury was above the four-car mean in all six categories and best of the four on acceleration and top speed. The Diplomat had the second-best acceleration but lost 0.508 on the road course, where it was slowest of the four by 0.33 seconds. The Crown Victoria’s best ergonomics and second-best brakes could not make up for the slowest 0–100 time and the lowest fuel figure. The book’s caution applies: “If, however, your needs differ from ours; i.e., top speed is not important to you, or 0-60 mph acceleration is more critical than 0-100, you would be well advised to make comparisons of the various vehicles using that data which is applicable to your operation.”