How do you figure? I have had the same carb on my car since it was new. I have never had to retune it because of climate change. It has been rebuilt once, but that is regular maintenance. However there is a difference when it is cold or hot outside, but nothing so extreme that it needs to be retuned every time. As long as your carb is set (choke, Idle, fuel/air mixture) correctly you should never have to mess with it. Granted EFI is supposed to be more efficient and sometimes better, but I still get 25-28 miles to the gallon at 65-70 with the cruise on.