Enthusiast Magazine Brake
Testing
Michael Austin, Technical Editor
Car and Driver
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Enthusiast Magazine Brake Testing
Main test site: Chrysler Chelsea Proving Grounds
h1.3-mile East/West Straightaway
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Enthusiast Magazine Brake Testing
Test equipment
hVBOX II DGPS
hBrake trigger
hWindows laptop
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Enthusiast Magazine Brake Testing
Test procedure
hFive 70-0 mph panic stops
hDistance corrected to 70 mph
hSecond-best stop is reported distance
New revisions to brake testing
◦ First stop, shortest stop, longest stop
◦ Tire warm-up procedure
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Enthusiast Magazine Brake Testing
Factors not related to braking distance
◦ Curb weight
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Enthusiast Magazine Brake Testing
Braking Distance Versus Curb Weight
7000
6000
Curb weight (pounds)
5000
4000
3000
2000
1000
0
140 150 160 170 180 190 200 210 220 230 240
70-0 mph braking distance (feet)
PAPER #
Enthusiast Magazine Brake Testing
Braking Distance Versus Curb Weight
7000
6000
Curb weight (pounds)
5000
4000
3000
2000
1000
0
140 150 160 170 180 190 200 210 220 230
70-0 mph braking distance (feet)
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Enthusiast Magazine Brake Testing
Factors not related to braking distance
◦ Curb weight
◦ Weight distribution
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Enthusiast Magazine Brake Testing
Braking Distance Versus Weight Distribution
70
65
% weight on front axle
60
55
50
45
40
35
30
140 150 160 170 180 190 200 210 220 230 240
70-0 mph braking distance (feet)
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Enthusiast Magazine Brake Testing
Relationship of tire type to braking distance
◦ Summer tire average:161 feet
◦ All-season tire average: 180 feet
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Enthusiast Magazine Brake Testing
Relationship of tire type to braking distance
Tire Type Average Braking Distance
Extreme Performance Summer 157
Max Performance Summer 160
Grand Touring Summer 166
Ultra High Performance Summer 166
Street/Sport Truck Summer 170
High Performance All Season 172
Crossover/SUV Touring All Season 178
Ultra High Performance All Season 179
Grand Touring All Season 179
Standard Touring All Season 180
Passenger All Season 180
Highway All Season 193
All Terrain 214
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Enthusiast Magazine Brake Testing
Other Peculiarities: Vehicle Type
Vehicle Type Average Braking Distance
Exotic Car 155
Sports Car 161
Luxury Car 166
Medium SUV 175
Small Car 177
Large SUV 177
Small SUV 178
Family Car 179
Hybrid/Eco 181
Minivan 185
Truck 208
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Enthusiast Magazine Brake Testing
Subjective evaluation: what we look for
◦ Pedal feel
◦ Pedal travel
◦ Feedback
◦ Ease of modulation
Brake system details not always considered in
reviews
Brake dust and pad life not much of a concern
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Enthusiast Magazine Brake Testing
Special brake testing
◦ String pot, pressure sensor
5-stop cycles from 100 mph
◦ 0.5-g stop followed by 4 panic stops
Highlights fade and recovery performance
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Enthusiast Magazine Brake Testing
Questions and Suggestions
◦ Improvements to test procedures
◦ What we should look for in reviews
◦ Further explanations for braking performance
◦ How future crash safety and emissions standards will
affect braking performance
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