I always see these threads and wonder where ya'll find these prices. I consistently get Toyota 0w20 from less than $4.50 per quart. Which is consistently less than either Pennzoil or Mobil1 at wal-mart. I have stuck with Toyota as I am confident in it and it is consistently a better price, and I like keeping a bit of a relationship with my parts guys at the dealer. Any brand is fine as long as it meets spec, but I do think there is some merit and staying with one brand consistently as the additive packs don't necessarily work together as well as they could, and since you don't ever get all the oil out, swapping back and forth all the time effects that. Will it ever make a difference, I doubt it. But I choose to stay with one oil. For me, that has been the Toyota stuff made by Mobil. If I went with Pennzoil or Mobil1, then more often than not I would have to pay more to stay with the same stuff each time.