I'm due for a oil change soon and am thinking of going to 0W-20 mobil 1 (synth). I've been using 5W-30 as recomended but it has been, and will continue to be, very cold (around -40C/F last few days). I can't plug my car in at work and she makes some awful noises when I start it after 10 hours in that cold. Anyone see a problem with 0W-20? (the warmest temp next few months will be well below freezing).