Hi Ian,

Certainly is alarming. I live in MPLS and I know that they are usually changing over to Oxygenated fuels for the winter season about this time. That typically leads to a reduction in overall fuel economy. That might be part of the reason.

Also - on tires - I just inflated mine to 42 PSI yesterday when it was 50 degrees out. They will drop about 4psi when the temps drop sub-zero.
All compressors will put a little moisture in the air-lines which get's transferred via the schrader valve in your valve stems into your tires. While the slight amount of moisture will not bother either the tire or the valve when above freezing, the schrader valves are known to leak if you introduce moisture laden air in the sub-freezing conditions. Living in the north has it's challenges - flat tires when -15f is one of them. I'm also curious if the moisture at sub-freezing will have any impact on the pressure sensors.
All of this adds up to why I inflated mine while still warm out.

Regards - Randy




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