As long as it is not in the red you are ok. I live in south texas and with the a/c on in traffic, the temps rise pretty good, but i have never had a problem. Well the only problem is that the a/c sucks when the car is idleing.

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1984 300SD Orient Red/ Palomino
1989 560SEC
2016 Mazda 6 6 speed manual
1995 Ford F-150 reg cab 4.9 5speed manual