Suppose you live in an area where extreme heat is common – like here in the Phoenix, Tempe and Chandler, Arizona area. You only have to glance around to see the aftermath. Mailboxes are melting, heat-related illnesses are more common, and roadways are buckling. So just imagine what all that heat is doing to your car. In most owners manuals the manufacturer gives two sets of vehicle maintenance requirements, normal and “severe service” conditions.