Contour Enthusiasts Group Archives Forums General General 10w30 or 5w30 Mobil1 post your reasoning

I've been using 10W-30, but next oil change will be 5W-30. By the way, if an oil changing place says they use Mobil 1 Synthetic, what kind are they using?? I only want to use Tri-Synthetic, but I think there are other types of Mobil 1 Synthetic out there, right??