# Cold and tire pressure warning **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** cr-v, honda\ **Created:** [January 16, 2018, 6:54pm UTC](https://community.cartalk.com/t/cold-and-tire-pressure-warning/111372 "2018-01-16T18:54:11Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![melott](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/melott/32/10827_2.png) [@melott](https://community.cartalk.com/u/melott)\ **Post date:** [January 16, 2018, 6:54pm UTC](https://community.cartalk.com/t/cold-and-tire-pressure-warning/111372/1 "2018-01-16T18:54:11Z")
I know that cold reduces pressure, but should it be enough to make my warning sensor go on? No tire is visibly underinflated. Too cold to be messing with a tire gauge. ---
**Author:** ![keith](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/keith/32/5518_2.png) [@keith](https://community.cartalk.com/u/keith)\ **Post date:** [January 16, 2018, 6:59pm UTC](https://community.cartalk.com/t/cold-and-tire-pressure-warning/111372/2 "2018-01-16T18:59:59Z")
It can. The TPMS does not care what the temperature is. ---
**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\ **Post date:** [January 16, 2018, 7:00pm UTC](https://community.cartalk.com/t/cold-and-tire-pressure-warning/111372/3 "2018-01-16T19:00:19Z")
Yes, it could be cold enough to set off the warning. If it’s too cold for you, you might go by a tire shop and have them inflate them to the recommended pressure. ---
**Author:** ![insightful](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/insightful/32/2732_2.png) [@insightful](https://community.cartalk.com/u/insightful)\ **Post date:** [January 16, 2018, 7:13pm UTC](https://community.cartalk.com/t/cold-and-tire-pressure-warning/111372/4 "2018-01-16T19:13:58Z")
> [@melott](#): > > Too cold to be messing with a tire gauge. Yeah, that could kill you… ;-] ---
**Author:** ![VOLVO-V70](https://avatars.discourse-cdn.com/v4/letter/v/8e8cbc/32.png) [@VOLVO-V70](https://community.cartalk.com/u/VOLVO-V70)\ **Post date:** [January 16, 2018, 7:21pm UTC](https://community.cartalk.com/t/cold-and-tire-pressure-warning/111372/5 "2018-01-16T19:21:52Z")
> [@melott](#): > > Too cold to be messing with a tire gauge. Go out check one, go back in have hot chocolate , repeat until all tires checked. ---
**Author:** ![MikeInNH](https://avatars.discourse-cdn.com/v4/letter/m/a587f6/32.png) [@MikeInNH](https://community.cartalk.com/u/MikeInNH)\ **Post date:** [January 16, 2018, 7:26pm UTC](https://community.cartalk.com/t/cold-and-tire-pressure-warning/111372/6 "2018-01-16T19:26:54Z")
> [@melott](#): > > I know that cold reduces pressure, but should it be enough to make my warning sensor go on? Easily…especially if the tire pressure was a little low before the cold hit. ---
**Author:** ![RandomTroll](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/randomtroll/32/12184_2.png) [@RandomTroll](https://community.cartalk.com/u/RandomTroll)\ **Post date:** [January 16, 2018, 7:48pm UTC](https://community.cartalk.com/t/cold-and-tire-pressure-warning/111372/7 "2018-01-16T19:48:12Z")
According to the ideal gas law (which is pretty close for air at atmospheric temperatures and pressures), pressure is a direct function of temperature (P × V = n × R × T). 0°F is 460° above absolute 0, so the difference between 0°F and 46°F would be 10%. -20°F and 72°F 20%. ---
**Author:** ![jtsanders](https://avatars.discourse-cdn.com/v4/letter/j/c2a13f/32.png) [@jtsanders](https://community.cartalk.com/u/jtsanders)\ **Post date:** [January 16, 2018, 8:46pm UTC](https://community.cartalk.com/t/cold-and-tire-pressure-warning/111372/8 "2018-01-16T20:46:09Z")
Yes. It’s normally about 30 here overnight. Last week it got down to 3 overnight. My daughter’s car tripped the TPS monitor. I checked it when the temperature was about 15 and about 15 minutes after she arrived. The lowest one was 27 psi. I think that is low enough to trip the TPS. ---
**Author:** ![B.L.E](https://avatars.discourse-cdn.com/v4/letter/b/848f3c/32.png) [@B.L.E](https://community.cartalk.com/u/B.L.E)\ **Post date:** [January 16, 2018, 9:17pm UTC](https://community.cartalk.com/t/cold-and-tire-pressure-warning/111372/9 "2018-01-16T21:17:38Z")
> [@RandomTroll](#): > > According to the ideal gas law (which is pretty close for air at atmospheric temperatures and pressures), pressure is a direct function of temperature (P × V = n × R × T). 0°F is 460° above absolute 0, so the difference between 0°F and 46°F would be 10%. -20°F and 72°F 20%. When using that formula, don’t forget that the “P” in that formula refers to absolute pressure, not gauge pressure. If you are at sea level add 14.7 psi to the tire’s gauge pressure, do the calculation, and then subtract 14.7 psi from the answer to get back to gauge pressure. Both pressure and temperature must be measured on an absolute scale in that formula. ---
**Author:** ![lion9car](https://avatars.discourse-cdn.com/v4/letter/l/59ef9b/32.png) [@lion9car](https://community.cartalk.com/u/lion9car)\ **Post date:** [January 16, 2018, 10:03pm UTC](https://community.cartalk.com/t/cold-and-tire-pressure-warning/111372/10 "2018-01-16T22:03:17Z")
> [@melott](#): > > Too cold to be messing with a tire gauge. Isn’t safety more important than minor temporary discomfort? ---
**Author:** ![VDCdriver](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/vdcdriver/32/30_2.png) [@VDCdriver](https://community.cartalk.com/u/VDCdriver)\ **Post date:** [January 16, 2018, 10:14pm UTC](https://community.cartalk.com/t/cold-and-tire-pressure-warning/111372/11 "2018-01-16T22:14:40Z")
> [@lion9car](#): > > Isn’t safety more important than minor temporary discomfort? Yup! This morning, out of an abundance of caution, I gloved-up and went into the garage to check my tire pressure as a result of the consistently low temps for the last few weeks. The vehicle mfr specifies 32 psi in the front, and 30 psi in the rear, and I measured 33/31 on my Accu-gage, so I felt that no further action on my part was necessary. However, I began with tire pressure of 35 front/33 rear a few weeks ago, in anticipation of a precipitous drop in temperatures. So, to answer the OP’s question… **Yes, the recent low temperatures can certainly trigger your TPMS warning light…if you didn’t take care to inflate the tires to a few psi over the mfr’s specification prior to the drop in temperatures.** If you didn’t take appropriate action earlier, then you really don’t have much choice but to brave the cold, and inflate the tires properly now that the temp has dropped. Plan ahead… 🤔 ---
**Author:** ![MikeInNH](https://avatars.discourse-cdn.com/v4/letter/m/a587f6/32.png) [@MikeInNH](https://community.cartalk.com/u/MikeInNH)\ **Post date:** [January 16, 2018, 10:21pm UTC](https://community.cartalk.com/t/cold-and-tire-pressure-warning/111372/12 "2018-01-16T22:21:22Z")
> [@melott](#): > > Too cold to be messing with a tire gauge. Have you tried changing a flat when it’s extremely cold out? A few winters ago went to White mountains for a ski trip. Sunday morning got in my 4runner to leave and the low pressure light was on. I got out my gauge and checked all the tires…it was -15 with a wind chill of -40. But I wasn’t going to chance getting a blowout 90 miles from home in that weather. ---
**Author:** ![shanonia](https://avatars.discourse-cdn.com/v4/letter/s/9de053/32.png) [@shanonia](https://community.cartalk.com/u/shanonia)\ **Post date:** [January 16, 2018, 10:58pm UTC](https://community.cartalk.com/t/cold-and-tire-pressure-warning/111372/13 "2018-01-16T22:58:15Z")
> [@MikeInNH](#): > > Have you tried changing a flat when it’s extremely cold out? Done it in the cold (maybe 10F) and snow, at night. Very glad I had practiced under better conditions in my garage. ---
**Author:** ![VOLVO-V70](https://avatars.discourse-cdn.com/v4/letter/v/8e8cbc/32.png) [@VOLVO-V70](https://community.cartalk.com/u/VOLVO-V70)\ **Post date:** [January 16, 2018, 11:14pm UTC](https://community.cartalk.com/t/cold-and-tire-pressure-warning/111372/14 "2018-01-16T23:14:58Z")
I had to use the free air machine at the convenience store for all four tires because the crummy temperature drop. I did two tires on one side, got in truck pulled out of the way and used heated seat feature for a few minutes then did the other side. ---
**Author:** ![RandomTroll](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/randomtroll/32/12184_2.png) [@RandomTroll](https://community.cartalk.com/u/RandomTroll)\ **Post date:** [January 17, 2018, 4:46pm UTC](https://community.cartalk.com/t/cold-and-tire-pressure-warning/111372/15 "2018-01-17T16:46:36Z")
> [@lion9car](#): > > Isn’t safety more important than minor temporary discomfort? Not to a lot of people I see on the road. ---
**Author:** ![Cavell](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/cavell/32/43396_2.png) [@Cavell](https://community.cartalk.com/u/Cavell)\ **Post date:** [January 17, 2018, 4:59pm UTC](https://community.cartalk.com/t/cold-and-tire-pressure-warning/111372/16 "2018-01-17T16:59:33Z")
can someone do the math? 32psi at 75F will result in what psi at 10f? ---
**Author:** ![RandomTroll](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/randomtroll/32/12184_2.png) [@RandomTroll](https://community.cartalk.com/u/RandomTroll)\ **Post date:** [January 17, 2018, 5:03pm UTC](https://community.cartalk.com/t/cold-and-tire-pressure-warning/111372/17 "2018-01-17T17:03:17Z")
> [@B.L.E](#): > > Both pressure and temperature must be measured on an absolute scale in that formula. Whoops! You’re right. I made a spreadsheet. For a tire inflated to 30 psi changes in temperature are about 50% greater: a tire inflated to 30 psi @ 0°F would be 34.5 psi @ 46°F, 38.9 @ 92°F ---
**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\ **Post date:** [January 17, 2018, 5:03pm UTC](https://community.cartalk.com/t/cold-and-tire-pressure-warning/111372/18 "2018-01-17T17:03:25Z")
“can someone do the math? 32psi at 75F will result in what psi at 10f?” I get 26.3 psig. ---
**Author:** ![RandomTroll](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/randomtroll/32/12184_2.png) [@RandomTroll](https://community.cartalk.com/u/RandomTroll)\ **Post date:** [January 17, 2018, 5:06pm UTC](https://community.cartalk.com/t/cold-and-tire-pressure-warning/111372/19 "2018-01-17T17:06:02Z")
> [@texases](#): > > I get 26.3 psig. I get the same. Here’s the math: calculate a constant using the temperature and pressure at time of inflation by adding 460 to the temperature and 14.7 to the pressure, divide that pressure by that temperature: (P0 + 14.7)/(T0 + 460) for P0 = 32 , T0 = 75 , that’s .0873. Use that constant to calculate for any T, remembering to add 460 to T then subtract 14.7 from the resultant P. A spreadsheet makes it easy. ---
**Author:** ![GorehamJ](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/gorehamj/32/24103_2.png) [@GorehamJ](https://community.cartalk.com/u/GorehamJ)\ **Post date:** [January 17, 2018, 7:18pm UTC](https://community.cartalk.com/t/cold-and-tire-pressure-warning/111372/20 "2018-01-17T19:18:44Z")
Cold can and does make TPMS warning lights come on. [Here is everything you need to know.](http://bestride.com/news/technology/heres-why-your-check-tire-pressure-light-is-coming-on-in-the-cold-this-weekend). It is pretty well established that as the temp drops by 10 degrees F, tire pressure drops by about 1 psi. So, I agree with texases. If you own a vehicle with a pressure display it is easy to confirm any week you see a big temp drop (or increase). [Next page](https://community.cartalk.com/t/cold-and-tire-pressure-warning/111372.md?page=2)