I know this has been rehashed a few times but what gives? I'm looking at buying a new truck soon, test drove a mega the other day in 90 degrees and partly cloudy conditions. We drove for about 20 minutes, in my opinion the A/C never adequately cooled off the interior. Idled in the parking lot for a while, and no cooler. This was with the A/C on full blast recirculate the whole time. Truck was a low mileage (1200) demo type deal, 5. 9 Laramie, '07. Drove a 6. 7, similarly equipped though it was cloudy outside, a bit cooler and A/C seemed to work just OK. Love the cummins, just not enough to sweat my *** off the whole time driving it in a southern summer.