# Expensive tire sidewall cracks; slow leak **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** tires\ **Created:** [July 11, 2025, 3:46am UTC](https://community.cartalk.com/t/expensive-tire-sidewall-cracks-slow-leak/200962 "2025-07-11T03:46:44Z")\ **Posts on this page:** 20\ **Page:** 6
**Author:** ![CapriRacer](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/capriracer/32/22_2.png) [@CapriRacer](https://community.cartalk.com/u/CapriRacer)\ **Post date:** [July 22, 2025, 5:59pm UTC](https://community.cartalk.com/t/expensive-tire-sidewall-cracks-slow-leak/200962/101 "2025-07-22T17:59:42Z")
I have friend - fellow retired tire engineer - and he reports that those infrared surface thermometers don’t correlate well to the tire air chamber temperature. That’s because the road surface can be hotter or cooler than the internal temperature - and measuring the tread surface tells you more about the road surface temperature than the temperature for the critical part of the tire. So its still better to monitor the pressure buildup - which shouldn’t exceed 10%, excluding ambient temperature effects ( 2% for every 10 degrees F.) ---
**Author:** ![davesmopar](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/davesmopar/32/41750_2.png) [@davesmopar](https://community.cartalk.com/u/davesmopar)\ **Post date:** [July 22, 2025, 6:19pm UTC](https://community.cartalk.com/t/expensive-tire-sidewall-cracks-slow-leak/200962/102 "2025-07-22T18:19:49Z")
Ha, I never noticed or paid attention to the TPMS sensors being able to read the temp of the air in the tire, so great, now I am gonna have to hook up my scanners to see if any of them can read the tire air temp… ---
**Author:** ![Nevada\_545](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/nevada_545/32/41232_2.png) [@Nevada\_545](https://community.cartalk.com/u/Nevada_545)\ **Post date:** [July 22, 2025, 6:24pm UTC](https://community.cartalk.com/t/expensive-tire-sidewall-cracks-slow-leak/200962/103 "2025-07-22T18:24:51Z")
> [@bing](#): > > Check pressure cold and don’t worry about the rest. …and use which pressure value? The one on the door placard or the one in the owner’s manual? The owner’s manual states to add 8 psi for high-speed operation, some are against this. This debate has been going on for years, Robert wants to compare the tire temperature of the base inflation pressure to the temperature using the higher value. ---
**Author:** ![ChrisTheTireWhisperer](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/christhetirewhisperer/32/34798_2.png) [@ChrisTheTireWhisperer](https://community.cartalk.com/u/ChrisTheTireWhisperer)\ **Post date:** [July 22, 2025, 6:42pm UTC](https://community.cartalk.com/t/expensive-tire-sidewall-cracks-slow-leak/200962/104 "2025-07-22T18:42:14Z")
For those who must know of their tires’ temperatures, Longacre Racing and other purveyors sell _pyrometers_, which measure the tread temperature - far more useful than knowing the temperature of the inflation gas inside (oxygen/nitrogen ). The probe penetrates about 1/16" into the tread surface. A cooler middle tread, or cooler outer tread on both sides, more than 2deg F, tells of over or underinflation. Much warmer tread to one side or the other might indicate issues with camber angle. ---
**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:** [July 22, 2025, 6:45pm UTC](https://community.cartalk.com/t/expensive-tire-sidewall-cracks-slow-leak/200962/105 "2025-07-22T18:45:11Z")
I do sometimes use the IR thermometer when airing up my tires, but I do that early in the morning when the car or truck is in the shade. Under these circumstances the air temp inside the tire should be that same or very close to the outside air temp. It is just for verification that all tires read the same. Then, using 20C or 68F as the base cold temp, I adjust the air pressure target by 0.1 psi for every degree that the actual temp varies from the base cold temp, up for hotter, down for cold. I also add 2 or 3 degrees because I do a lot of highway driving. But there are limits that I impose for my self on this, no more than 4 psi above the placard or more than 2 below. ---
**Author:** ![ChrisTheTireWhisperer](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/christhetirewhisperer/32/34798_2.png) [@ChrisTheTireWhisperer](https://community.cartalk.com/u/ChrisTheTireWhisperer)\ **Post date:** [July 22, 2025, 6:59pm UTC](https://community.cartalk.com/t/expensive-tire-sidewall-cracks-slow-leak/200962/106 "2025-07-22T18:59:36Z")
> [@VOLVO-V70](#): > > Wonder if the Moderators could put a warning label on > any post by RG that it is nonsence or just plain wrong? Yet when I go about correcting such misperceptions or misinformation, I get a warning, suspension, etc. I guess I have “Charlie Brown” syndrome, lol! Glad to be back by the way. I will spend more time challenging suppositions and less time attacking others’ ages or other personal attributes. ---
**Author:** ![db4690](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/db4690/32/2583_2.png) [@db4690](https://community.cartalk.com/u/db4690)\ **Post date:** [July 22, 2025, 7:03pm UTC](https://community.cartalk.com/t/expensive-tire-sidewall-cracks-slow-leak/200962/107 "2025-07-22T19:03:42Z")
How about you spend NO time attacking other people’s ages and other personal attributes ---
**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:** [July 22, 2025, 8:27pm UTC](https://community.cartalk.com/t/expensive-tire-sidewall-cracks-slow-leak/200962/108 "2025-07-22T20:27:17Z")
> [@ChrisTheTireWhisperer](#): > > Glad to be back by the way. I will spend more time challenging suppositions or misinformation Will that include your own ? ---
**Author:** ![lion9car](https://avatars.discourse-cdn.com/v4/letter/l/59ef9b/32.png) [@lion9car](https://community.cartalk.com/u/lion9car)\ **Post date:** [July 22, 2025, 8:33pm UTC](https://community.cartalk.com/t/expensive-tire-sidewall-cracks-slow-leak/200962/109 "2025-07-22T20:33:50Z")
> [@davesmopar](#): > > Ha, I never noticed or paid attention to the TPMS sensors being able to read the temp of the air in the tire, so great, now I am gonna have to hook up my scanners to see if any of them can read the tire air temp… My wife’s BMW X5 reads the temperature and displays what the pressure should be at that temperature (assuming you correctly calibrated the system when the tires are cold). ---
**Author:** ![ChrisTheTireWhisperer](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/christhetirewhisperer/32/34798_2.png) [@ChrisTheTireWhisperer](https://community.cartalk.com/u/ChrisTheTireWhisperer)\ **Post date:** [July 22, 2025, 8:55pm UTC](https://community.cartalk.com/t/expensive-tire-sidewall-cracks-slow-leak/200962/110 "2025-07-22T20:55:16Z")
All I would ask for is, pre-suspension, examples of “my own”. Thank you. ---
**Author:** ![db4690](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/db4690/32/2583_2.png) [@db4690](https://community.cartalk.com/u/db4690)\ **Post date:** [July 22, 2025, 10:49pm UTC](https://community.cartalk.com/t/expensive-tire-sidewall-cracks-slow-leak/200962/111 "2025-07-22T22:49:47Z")
@ChrisTheTireWhisperer You’ll have to work EXTREMELY hard to regain our trust I suggest you NEVER private message anybody EVER again ---
**Author:** ![ChrisTheTireWhisperer](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/christhetirewhisperer/32/34798_2.png) [@ChrisTheTireWhisperer](https://community.cartalk.com/u/ChrisTheTireWhisperer)\ **Post date:** [July 22, 2025, 11:18pm UTC](https://community.cartalk.com/t/expensive-tire-sidewall-cracks-slow-leak/200962/112 "2025-07-22T23:18:01Z")
I always wondered how a DiscounTire or other tire store would calibrate a TPMS system, considering it may be the middle of the day, plus tires hot from driving there, etc. ---
**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:** [July 24, 2025, 2:12am UTC](https://community.cartalk.com/t/expensive-tire-sidewall-cracks-slow-leak/200962/113 "2025-07-24T02:12:27Z")
PV=NRT , the ideal gas law. Because N, R, and V don’t change, you can figure out the temperature of the air inside your tire from the pressure. Do those TPMS measure it precisely enough? T is absolute, which is about 520°R for 70°F, so T would need to increase by 52° to result in a 10% increase in pressure. If you inflate to 30 psi, an increase of 17° would be 1 psi more, which seems likely. ---
**Author:** ![Nevada\_545](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/nevada_545/32/41232_2.png) [@Nevada\_545](https://community.cartalk.com/u/Nevada_545)\ **Post date:** [July 24, 2025, 2:52am UTC](https://community.cartalk.com/t/expensive-tire-sidewall-cracks-slow-leak/200962/114 "2025-07-24T02:52:04Z")
> [@RandomTroll](#): > > Because N, R, and V don’t change, you can figure out the temperature of the air inside your tire from the pressure. Very good, tell the group how much pressure increase you observed after driving 30 minutes @ 80 mph, both with a base pressure of 30 psi and 36 psi. ---
**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:** [July 24, 2025, 11:44am UTC](https://community.cartalk.com/t/expensive-tire-sidewall-cracks-slow-leak/200962/115 "2025-07-24T11:44:28Z")
I don’t understand your question. If a tire is ‘cold’, which is to say the same temperature as the ambient air, at 70°F, and 30 psi, then 31 psi after 30 minutes of driving, its temperature has increased by 520/30 = 17⅓°F. I can imagine a TPMS that reads to .1 psi, which would yield a precision of 1.7°F. ---
**Author:** ![ChrisTheTireWhisperer](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/christhetirewhisperer/32/34798_2.png) [@ChrisTheTireWhisperer](https://community.cartalk.com/u/ChrisTheTireWhisperer)\ **Post date:** [July 24, 2025, 12:16pm UTC](https://community.cartalk.com/t/expensive-tire-sidewall-cracks-slow-leak/200962/116 "2025-07-24T12:16:15Z")
I think the term ‘cold’, in a tire context, is being over-analyzed, by many. Cold simply means, either, earliest in the morning not yet driven, or, not driven for at least 3 hours. Local ambient temperature figures little, if any, into this context. I would like to know the groups thoughts on the following two cold tire inflation scenarios. The first one represent s fairly steady daily temperatures, with a rising trend typical of June in north American climates. Instead of adjusting cold tire pressures at the coldest part of day, one could argue for adjusting them at the mid-point temperature, perhaps 3-4 hours after early dawn, as represented by the blue line. ![Tire Pressure vs Ambient Temperature - 01 - Steady State](https://global.discourse-cdn.com/cartalk/original/3X/f/0/f04ce110230af4a3d85b0ea51d89e2accdaf5756.jpeg) The second daily ambient temperature model is probably more realistic, at least post-2000. How one handles that second model is anyone’s guess… ![Tire Pressure vs Ambient Temperature - 02 - Variable Daily Temps](https://global.discourse-cdn.com/cartalk/original/3X/f/f/ff3f0d5a46c1469b030f91b8b591e81bbb5a96ee.jpeg) ---
**Author:** ![TwinTurbo](https://avatars.discourse-cdn.com/v4/letter/t/8baadc/32.png) [@TwinTurbo](https://community.cartalk.com/u/TwinTurbo)\ **Post date:** [July 24, 2025, 12:43pm UTC](https://community.cartalk.com/t/expensive-tire-sidewall-cracks-slow-leak/200962/117 "2025-07-24T12:43:30Z")
> [@ChrisTheTireWhisperer](#): > > Cold simply means, either, earliest in the morning not yet driven > > Local ambient temperature figures little, if any, into this context. So you think a tire that has sat overnight is not at ambient temperature? ---
**Author:** ![lion9car](https://avatars.discourse-cdn.com/v4/letter/l/59ef9b/32.png) [@lion9car](https://community.cartalk.com/u/lion9car)\ **Post date:** [July 24, 2025, 2:06pm UTC](https://community.cartalk.com/t/expensive-tire-sidewall-cracks-slow-leak/200962/118 "2025-07-24T14:06:43Z")
> [@ChrisTheTireWhisperer](#): > > Instead of adjusting cold tire pressures at the coldest part of day, one could argue for adjusting them at the mid-point temperature, perhaps 3-4 hours after early dawn, as represented by the blue line. One could argue that, but one would be wrong. When the manufacturer figures out the recommended tire pressure, they take into account that the temperature rises during the day. ---
**Author:** ![TwinTurbo](https://avatars.discourse-cdn.com/v4/letter/t/8baadc/32.png) [@TwinTurbo](https://community.cartalk.com/u/TwinTurbo)\ **Post date:** [July 24, 2025, 2:12pm UTC](https://community.cartalk.com/t/expensive-tire-sidewall-cracks-slow-leak/200962/119 "2025-07-24T14:12:07Z")
The other point to make is that people can make more out of this than necessary or warranted. It’s really not that critical. If it was, you would see much more detail in the process of pressurizing your tires. ---
**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:** [July 24, 2025, 2:37pm UTC](https://community.cartalk.com/t/expensive-tire-sidewall-cracks-slow-leak/200962/120 "2025-07-24T14:37:07Z")
When I think of ‘cold tire pressure’, I interpret that to mean ‘before any driving that day’. I’m fine checking my tires at noon, as long as I haven’t driven up until then. [Previous page](https://community.cartalk.com/t/expensive-tire-sidewall-cracks-slow-leak/200962.md?page=5) [Next page](https://community.cartalk.com/t/expensive-tire-sidewall-cracks-slow-leak/200962.md?page=7)