said by Subaru:if my car's LCD display works in 12F then it should be no reason for this
All LCDs are not created equal. The LCDs used in your car were likely designed for improved low temperature operation.
As for the LCDs used in dirt-cheap electronic devices like electronic tire pressure gauges, they don't work so well in the cold. The tire pressure gauge I used to have (see other thread about throw-away electronics) was almost impossible to read below -10C. Calculators are just as bad, they use the same type and grade of dirt cheap LCDs.
I recently purchased a dial type tire pressure gauge for $5, and guess what it works fine in the cold.