TPMS in extreme cold

[G8H8]

Its -18 with a wind chill of -35 outside. Went out snowblowing and noticed when I cranked my car the TPMS showed check left rear. It showed that the tire is at 27lbs. I have also noticed when we fill them in the summer to 34 the tpms shows 30-32lbs. Theses things aren't very accurate. My left rear is fine.

[R.Penguin]

Its -18 with a wind chill of -35 outside. Went out snowblowing and noticed when I cranked my car the TPMS showed check left rear. It showed that the tire is at 27lbs. I have also noticed when we fill them in the summer to 34 the tpms shows 30-32lbs. Theses things aren't very accurate. My left rear is fine.
I don't think they are dead nuts accurate and temp. changes do affect tire pressure a lot. I look at mine to warn me if a tire is dangerously low, or flat. I can't remember all the times someone in a parking lot has told me "Hey, you got a low tire." A lot of peeps just aren't used to seeing low profile tires on a full size 4 door sedan.

-35F !!!!!!! F*ck me!

[JimmyJazz]

My TPMS show's 2-3lbs less than two different guages also.

[jnak]

Temperature changes will affect your tire pressures. Especially when it's really cold out. That's why you should check your pressures regularly.

My TPMS seems to be fairly accurate, in temperatures close to what you're at.

[TPMSXpress]

Let me start by stating that I work for Schrader Electronics and we manufacture the Epsilon II snap-in TPM sensors that our G8's are equipped with, so I can speak to this subject with some level of certainty.

First, the inflation condition you are seeing is perfectly normal and expected. The air pressure in your tires and tire tread life are affected by temperature, road conditions and driving speed.

Tires are permeable and can lose up to 2 psi per month. More air is lost in hot weather as the pores in the tire material expand. To maintain proper inflation levels, we recommend you measure the air pressure in your vehicle's tires at least once a month.

Changes in ambient temperature cause changes in tire pressure. This is particularly important in Northern states and Canada's climate where temperature swings of 20 to 30ºC are not uncommon. Every 5ºC change in temperature results in about 1 psi change in pressure, so a temperature drop of 15ºC would result in 10% or 3 psi under-inflation.

Second, the pressure sensors used in all TPM sensors are subject to variation. This must be accounted for, considering our sensors are found in one of the most grueling, harsh locations on a vehicle. The electronics, which demand precision, are constantly subjected to the violence associated with high speed rotation, tire generated heat and ambient temperature swings. In a word, it is NOT the place you would want to try and design complex electronics to survive...but we do.

Every pressure sensor (in this case, these are GE Sensonor sensors) will vary slightly. GM and TREAD Act specifications allow a variation of around +/-3psi on the transmitted pressure values. Most of our Epsilon II sensors are very accurate, while some will read around 1-2psi different than a hand gauge may show. Keep in mind too, most hand gauges are not calibrated and can vary wildly. We do have other versions of TPM sensors which are much more consistent and accurate...but certain customers (clears throat) do not yet wish to pony up the $$$ for that technology.

Don't hesitate to let me know if you have any other questions, or if you ever need replacement sensors.

[-Ray-]

We get large changes in temperatures here. Last night it was 52 (11C) degrees F and now it's 25 (-4) degrees.

[SSD]

I have one that reads -1 compared to an accurate hand gauge, and another that reads +3. Go figure...

[STROBI]

I need a set desperately for my 2010 camaro winter wheels...can you please contact me at mjstroh@vcn.com Thanks



Let me start by stating that I work for Schrader Electronics and we manufacture the Epsilon II snap-in TPM sensors that our G8's are equipped with, so I can speak to this subject with some level of certainty.

First, the inflation condition you are seeing is perfectly normal and expected. The air pressure in your tires and tire tread life are affected by temperature, road conditions and driving speed.

Tires are permeable and can lose up to 2 psi per month. More air is lost in hot weather as the pores in the tire material expand. To maintain proper inflation levels, we recommend you measure the air pressure in your vehicle's tires at least once a month.

Changes in ambient temperature cause changes in tire pressure. This is particularly important in Northern states and Canada's climate where temperature swings of 20 to 30ºC are not uncommon. Every 5ºC change in temperature results in about 1 psi change in pressure, so a temperature drop of 15ºC would result in 10% or 3 psi under-inflation.

Second, the pressure sensors used in all TPM sensors are subject to variation. This must be accounted for, considering our sensors are found in one of the most grueling, harsh locations on a vehicle. The electronics, which demand precision, are constantly subjected to the violence associated with high speed rotation, tire generated heat and ambient temperature swings. In a word, it is NOT the place you would want to try and design complex electronics to survive...but we do.

Every pressure sensor (in this case, these are GE Sensonor sensors) will vary slightly. GM and TREAD Act specifications allow a variation of around +/-3psi on the transmitted pressure values. Most of our Epsilon II sensors are very accurate, while some will read around 1-2psi different than a hand gauge may show. Keep in mind too, most hand gauges are not calibrated and can vary wildly. We do have other versions of TPM sensors which are much more consistent and accurate...but certain customers (clears throat) do not yet wish to pony up the $$$ for that technology.

Don't hesitate to let me know if you have any other questions, or if you ever need replacement sensors.

[BluYa76]

It's funny yours is reading the left rear low, cause mine does this every time the car is sitting for a long period with low temps (even though the tire on the opposite side reads the same). Never understood why it keeps picking on the left rear. :wacko:

[-Ray-]

I need a set desperately for my 2010 camaro winter wheels...can you please contact me at mjstroh@vcn.com Thanks

They are a vendor here. If you need them, give them a call.
The chances of them looking in an old thread to find your request is slim.

[Blackrider]

Wind chill has no bearing on the physical temperature of something, if you have a ambient air temperature of -18 and a wind chill of -35 all objects sitting outside will only cool to -18. Wind Chill is simply the effect of wind on the body, its making it "Feel" colder than it is.

Just and FYI as I see you included wind chill, a lot of people get that mixed up.

[-Ray-]

That and his post is almost a year old. :D