Discussing questions of preferable SAE grades or chosing the right one we often refer to or at least try to be as much as closer to OEM recommendations. These recommendations mainly consider Grade vs. Ambient temperature. However, they never consider an eventual impact of a road temperature. In summer days, as you may notice, the temperature of an ashpalt paved road is usually 10-20 C higher than that of an air. Thus, expecting that the temperature would not exceed 30-35 C, your car, in fact, is passing hours in a traffic jam or rolling over a highway stressed by 40-50 C heat coming out from the pavement. What do you think about this impact ?