After reading a little bit about how mileage varies throughout the year and how cold temperatures make the engine work harder etc, I'm wondering if there is a best time of the year to buy one's car. Specifically with reference to future car longevity and mileage performance. For example, would buying a car in September or October when temperature extremes in Michigan are rare yield a healthy break-in period for the car versus buying the car in January when winter extremes would force tough engine use? The idea being that by the time tough temperatures come around the car is completely broken in and "established."

Obviously where one lives would affect the specific time of the year to buy if this theory is not groundless.

 

I think that your theory is groundless. People have been buying and breaking in cars in MI for about one hundred years. If there were any serious concerns, Detroit auto makers would have had "If You Live In Michigan" break-in procedures in new car woner's manuals. But of course, NO car maker wants your car to last forever.