Runflats swapped for all season tires

[Mbjvi]

Just had 4 new all season 20s put in staggered array (Ft 275/40R20 106(V or >)
Rr 315/35R20 110(V or >) at F 36, R 41 psi) same size as the runflats.
Week later low pressure sensor alert and all 4 low pressure (F now 30, R now 35) with one rear tire at 24psi.
Wheels original no changes.
What is the problem?

[smyles]

Did they fill'em with summer air?

[turboawd]

Originally Posted by Mbjvi

Just had 4 new all season 20s put in staggered array (Ft 275/40R20 106(V or >)
Rr 315/35R20 110(V or >) at F 36, R 41 psi) same size as the runflats.
Week later low pressure sensor alert and all 4 low pressure (F now 30, R now 35) with one rear tire at 24psi.
Wheels original no changes.
What is the problem?

Colder weather? Air shrinks.

[RED_Y_]

Happened to me many times when I lived in Tahoe. 80 in August vs 20 in November will do the trick, put some cold winter air to the proper pressure, reset TPMS and drive your car around the block. Problem solved.

[pennsiveguy]

Originally Posted by smyles

Did they fill'em with summer air?

That's happened to me, both at the tire shop and in my shop at home. Fill the tires with 70-degree air when the tires and rims are at 70 degrees, and then drive out into sub-freezing weather and watch the pressures and temps dive in the iDrive Tire Pressure Monitoring screen. In extreme -25 cold I've even had tires pull away from the beads and go totally flat.

[hufington]

Just happened to me when I swapped the P Zeros with Vredestein all seasons. Like mentioned above, pumping in cold air when tires are cold does the trick.

[andrewmr]

Originally Posted by Mbjvi

Just had 4 new all season 20s put in staggered array (Ft 275/40R20 106(V or >)
Rr 315/35R20 110(V or >) at F 36, R 41 psi) same size as the runflats.
Week later low pressure sensor alert and all 4 low pressure (F now 30, R now 35) with one rear tire at 24psi.
Wheels original no changes.
What is the problem?

As others have already said, you just need to inflate the tires now that the temps have dropped.

I would keep an eye on the one that dropped to 24 as that's a pretty big delta.