When you mix, for example a 5w30 with a 15w50, what is the actual end result? Will I get a true 7.5w40 at a 50/50 ratio? I ask only because in Western Canada (Calgary South) I am unable to find 0w40 M1. I can find DOZENS!! of liters of GC 0w30 however. I have seen numerous mention of ...add a little of this weight or that; DOES IT WORK ???? I ask because my 93 Integra with 360 000km likes a little thicker oil, but winter is coming.........! One more thing...GC IS green!!!; kinda freaks me out; not sure why...oh well.