# Tire pressure

**URL:** <https://community.cartalk.com/t/tire-pressure/26819>\
**Category:** General Discussion\
**Created:** [February 22, 2009, 4:14pm UTC](https://community.cartalk.com/t/tire-pressure/26819 "2009-02-22T16:14:13Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Namber](https://avatars.discourse-cdn.com/v4/letter/n/6a8cbe/32.png) [@Namber](https://community.cartalk.com/u/Namber)\
**Post date:** [February 22, 2009, 4:14pm UTC](https://community.cartalk.com/t/tire-pressure/26819/1 "2009-02-22T16:14:13Z")

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How on earth does the tire pressure indicator on the dashboard know the tires are low?

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**Author:** ![americar](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/americar/32/42_2.png) [@americar](https://community.cartalk.com/u/americar)\
**Post date:** [February 22, 2009, 4:30pm UTC](https://community.cartalk.com/t/tire-pressure/26819/2 "2009-02-22T16:30:48Z")

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Either by the ABS system monitoring a sudden change in the rolling circumference of one tire compared to the others, or by a actual pressure sensors in the wheel.

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**Author:** ![Namber](https://avatars.discourse-cdn.com/v4/letter/n/6a8cbe/32.png) [@Namber](https://community.cartalk.com/u/Namber)\
**Post date:** [February 22, 2009, 6:57pm UTC](https://community.cartalk.com/t/tire-pressure/26819/3 "2009-02-22T18:57:33Z")

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Are you guessing one or the other or are both methods used?

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**Author:** ![Joseph\_E\_Meehan](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/joseph_e_meehan/32/21_2.png) [@Joseph\_E\_Meehan](https://community.cartalk.com/u/Joseph_E_Meehan)\
**Post date:** [February 22, 2009, 7:31pm UTC](https://community.cartalk.com/t/tire-pressure/26819/4 "2009-02-22T19:31:59Z")

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Are you guessing one or the other or are both methods used?

Both methods are used depending on the make model and year.