How do you determine what is the optimum tire pressure for best fuel efficiency?
October 3, 2009 in Engineering
Did you know that you can save fuel and run your car on water
Carbonbased Lifeform asked:
Do you just go by the pressure marked on the tires and pump up the tire to that pressure?
Did you know that you can save fuel and run your car on water
The tire pressure listed on the tires is a maximum. DO NOT inflate to that pressure. The optimum tire pressure for your car is on a sticker on the drivers side door sill. That is the pressure to fill your tires to.
Empirical observation.
Doug
To expand on the previous answers:
The pressure marked on the tire is the maximum pressure which the tire is capable of working at. By filling the tire to this pressure, you expand it such that the bottom of the tire (the surface touching the road) bulges. This means that you have less area touching the ground, and you will have less traction.
Your vehicle should have a manual that states what the optimum tire pressure is. The reason that the manual can quote an optimum pressure for a variety of tire types (all season, winter, summer, etc) is because the weight of the car does not change very much, and therefore the total amount of force to keep the car tires with the maximum surface area on the road doesn’t change very much. (The internal pressure force of the tires, distributed on four wheels, equals the weight of the car.)
Summation: Read the owner’s manual for your vehicle and it should give you the optimum tire pressure. This is always the pressure you want to inflate your tires to.
The optimum pressure for the best fuel efficiency is the maximum pressure the tire can withstand. The higher the pressure the less friction.
The pressure selected by the automobile manufacturer and tire manufacturer is a compromise to address fuel efficiency and the comfort for the passengers.
Stick with the recommended pressure in your owners manual and you stand a better chance of not having a blowout and a possible loss of control and really bad accident.
How you drive, that is, how you accelerate, slowdown and the speed you travel at has a much bigger impact on mpg than just raising your tire pressure.