The Effect of Tire Pressure on Stopping Distance By: Dominic Corbett

Chevy Celebrity The car being used to test is a 1987 Chevy Celebrity It has 2 disk brakes and 2 drum brakes There is no antilock brake system All the tires have good tread

My Chevy Celebrity

How Brakes Work Car brakes work by applying pressure to the decelerator pedal This forces brake fluid to close calipers around rotors The calipers rubbing on the rotors creates friction and eventually stops the tires

Purpose To find if tire pressure really does effect stopping distance in fair weather conditions This will show how important it is to check the tire pressure on your own car

Hypothesis I believe that when the tire pressure is at the lowest it will stop the slowest. The recommended tire pressure will probably stop the car the fastest. Also having too much pressure in the tires will be dangerous and cause stopping distance to decrease

Materials 1987 Chevy Celebrity Tape measure Chalk Tape Air compressor Tire pressure gauge

Procedure First inflate all tires to the same pressure Mark a line on the pavement Next in a safe, closed, and dry road bring the car to 20 mph Put the car in neutral Once passing the tape jam on the brakes as hard as possible till stopping Mark where the front end stopped and measure from the stopping line

The Procedure

Data

Data cont. 35 psi30 psi25 psi Trial Trial Trial Average

Conclusion Overall the stopping distances were fairly close The results matched the hypothesis One thing I noticed when testing the lower pressure was that the tires would lock up and skid considerably further

Wheels Locking Up

Benefits of Checking Tire Pressure Reduced stopping distances, Better handling of the vehicle in a curve or in a lane change maneuver less chance of hydroplaning on a wet surface, which effects both stopping distance loss of control.

Application This applies to the real world by showing the effect of tire pressure on stopping distance The relation to agriculture is through the machinery the machines have tires and if they are not inflated properly they create inefficiencies Hopefully this shows how important it is to routinely check tire pressure