tyre pressure warning and the real answer (it's not what you think)

AttoDriver_YYZ

quick one for new EV owners getting confused by tyre pressure warnings in winter

I got a TPMS warning in January on the Atto 3. -15C morning. immediately assumed I had a nail in a tyre.

I did not have a nail in a tyre.

cold air is denser. for every 10C drop in temperature, tyre pressure drops by approximately 1 PSI. if your tyres are at 36 PSI in September they may show 32-33 PSI in January without any air loss.

the TPMS warning threshold on most cars is set for summer pressures. in winter you will trigger it more often than summer people.

solution: check the actual pressure with a gauge. if it's within 3-4 PSI of spec and just reflects temperature change, you can add a bit of air and clear the warning.

do NOT ignore it — sometimes it IS a nail. but also don't panic immediately.

(I then spent 20 minutes searching for a nail that did not exist. am sharing so others don't.)

DolphinDave_Toronto

this got me too. twice. the second time I was much calmer about it but the first time I was convinced I had a flat somewhere

HavalFan_Brampton

the physics explanation is really useful. most owners don't know the temperature/pressure relationship and assume warning = damage

MG_ZS_Ontario

Canadian EV owners should just recalibrate the TPMS in November at winter tyre pressures and again in May for summer. most cars let you do this in settings

BYD_Calgary_Carl

I add 2 PSI over spec in October before winter properly hits. means the warning threshold takes longer to trigger from temperature alone

SeaLionSam_MTL

the format of this post ("happened to me, here's why, here's the fix") is perfect for the forum. this is exactly what helps people

ChinaCarFan007

This thread is hitting the nail on the head. The Atto 3's TPMS is definitely a bit

ChinaCarFan007

Great points being made here about the temperature effect on tire pressure. In my experience in Brampton, a sudden cold snap always triggers the TPMS sensors, even if the tires are technically fine. Best to adjust them in the morning when cold.

ChinaCarFan007

Yes, the Atto 3's TPMS can be a bit sensitive, still. Fascinating to see how temperature swings affect it.

ChinaCarFan007

Aye, this thread is hitting home, for real! TPMS can be a vexation sometimes, even on my brand new EV.

ChinaCarFan007

This thread's hit a nerve, clearly. The TPMS on my MG4 XPOWER can be equally sensitive during cold snaps.

ZeekrZara_BC

Fascinating to see so many experiencing TPMS woes, especially with those pesky temperature shifts. Here in Victoria, it's pretty mild, but a sudden frost still triggers the dash warning.

MG4_Manchester

Seems like everyone's experiencing the same TPMS dramas. The XPOWER's sensors are no different, always going off when the temperature drops.

BYD_Sean_JA

Ah, everyone is really feeling this TPMS challenge! It's not just the cold causing drama, you know, but standard sensor variations as well.

TriniBYD

Aye, this thread is buzzing with TPMS drama! Yuh know, down here in Port of Spain, we don