I finally got to test this Volt in really hot weather with the AC climate control on ECO. Previous gas cars that I have had without climate control, there would be no difference between really hot or just warm weather. Turn on the AC and watch your gas tank empty faster. With the Volt climate control, the range will vary. In moderately warm weather up to low 80’s, I see about a 10% lower range, right around 45 miles, instead of the 50 miles I easily get in the summer. In really hot weather in the 90’s and blasting the AC in ECO steady, there is about a 25% lower range, all the way down to 38 miles, where I would normally get 50 miles or more.
Last summer I did not get to test it much in really hot weather, plus this year for some reason I need more AC.