[pecivil]

no, 0-40 is not for cold climates. I would never use 15-50. It is much too thick, no matter where you are, or how hot is it outside.

read the articles in the link I gave below. Again, it is long, but if you can follow it, you will understand why 0-40 or even 0-30 is the better oil to use.

15-50 is needlessly increasing the amount of time that it takes the oil to reach operating temp at startup. This results in an increased time to achieve proper lubrication, and an increased time of extreme engine wear. All oils achieve the proper viscosity at operating temps.

The real variable is how long it takes the oil to get to proper temperature (i.e. to thin out) AT STARTUP.

the thicker the oil, the much, much longer it takes.

Anyway, on my boxster, there is a sticker on the trunk lid near the oil filler neck that clearly states "Use Mobil 1 0-40 ONLY"