Here in Northern Germany we also had up to 86 degree, maybe more. The mileage was perfect but not comfortable because I didn't use the air condition to save fuel. And when driving more than 50mph I closed the windows to reduce air resistance. But the result was great. I nearly reached the best mileage since I have this car.
I wonder which influence the humidity has. Here we haven't got any drop of rain for five weeks now.
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