NCJ Number
165471
Date Published
August 1997
Length
89 pages
Annotation
This report presents findings from the National Law Enforcement and Corrections Technology Center's evaluation of the following 1997 patrol vehicle tires: Firestone Firehawk PV40, General XP-2000 V4, and Goodyear Eagle RS-A.
Abstract
Each brand of tire was tested on a Ford Crown Victoria and a Chevrolet Caprice, the two vehicles that represent the vast majority of police cars currently in use. This report presents the test objective, test methodology, formulas, test data, and comparison chart for the static circle test on dry pavement and wet pavements, the serpentine test on both dry and wet pavements, the stopping distance test on both dry and wet pavements, and the high-speed handling test. Tire wear measurements were also conducted. The static circle test on both dry and wet pavements was designed to determine the road-holding performance characteristics of the test tires in a steady-state turning situation. The serpentine test on both dry and wet pavements was designed to determine each tire's transient response characteristics and performance while weaving through pylons at 60 mph. Serious deficiencies in transient response will result in longer elapsed times, slower speeds, and a lower overall score on this portion of the evaluation. The stopping distance test on both dry and wet pavements involved a simulated "panic" stop of the vehicle at an approach speed of just over 60 mph. Deficiencies in tire adhesion would result in longer stopping distances and a relatively lower score on this portion of the evaluation. The high-speed handling test assessed each tire's performance on a 1.43-mile road-racing type course with high-speed curves, low-speed corners, and straightaways, so as to simulate actual pursuit conditions in the field. This was designed to test the tire's blending of transient response, cornering, and rapid deceleration. The testing also determined each tire's wear characteristics when subjected to the entire performance evaluation. This report presents the test scores for each type of tire for each of the two vehicles on which the tires were tested.