[lkchris]

Your motor is going to run at the thermostat-controlled temperature whether you're driving in Texas or Maine. Maintain your cooling system, of course. Your engine generates most heat not in Texas, but when the motor is working hardest, e.g. on a top speed extended Autobahn run. You'll never do that, but your car's cooling system can handle that.

Porsche A40-spec oils are all synthetics, and with synthetics there are no temperature problems ... basically your only concern is starting a cold engine and how cold ambient temperature is at the time.

A few years back I read Mobil specs for all their synthetics ... there was no difference in cold pour point between 0W, 5W, and 10W. Iirc, all were -55 F. 15W-50 was a few degrees warmer.

40 is 40 no matter what the W number is. Etc.

Follow owners manual; don't worry, be happy.