Q: I fill up my gas tank and I put unleaded plus when it is required to put unleaded regular and I always put that on the highway I n

Hi Patricia. Thanks for contacting us today. While running the recommended fuel to your car is important, it’s less likely that the swap to a higher octane has created this temperature issue. It’s most likely that there is a different mechanical problem - such as an obstruction of debris in the cooling lines, or a faulty coolant temperature sensor or radiator thermostat. It’s also possible that a fuel system component is clogged with excessive carbon deposits or needs to be serviced. I think the best thing to do have a professional mechanic complete an on-site inspection to determine what is causing this problem - so that any repairs or service can be completed before damage occurs.