I see all this cheap dino oil at Canadian Tire, Zellers and other small stores and I was wondering if it's possible to "prop up" the cheap oil with some additive in a bottle like Valvoline Maxlife. I understand that while almost all oils now are rated to at least API SL, the cheap stuff might not have too great of an additive package which the more costly dino oils would certainly have. So therefor I was wondering about the possibility of boosting the cheap oil's additive properties with some off-shelf additive in a bottle stuff.