So I have 2015 Sahara with Bridgestone tires that say psi should be 35. Now that the weather has been very cold out here in New York my psi has been telling me I need air in almost every tire. I stopped at a tire shop today and asked them to fill all the tires to 35 but when I got in my car it reads 42 on all 4. Is this normal or should I be concerned that they're over inflated? It's my first brand new JEEP and I just want to make sure I'm maintaining everything correctly.