^That is about what it comes down to, "brand loyalty". I laugh when I think of our families' '77 Volare Station wagon, slant six, at the end of it's life, it reached 417K miles. All the while, not changing the oil (my mom couldn't ever remember), using whatever oil was the cheapest. Let me add, we got the car with 4,617 miles from the grand parents. What else, when my brother got it, we changed the oil every 3K or sooner, using FRAM filters and whatever oil, thinking it was "Flag" oil from Schuck's Auto Supply or Napa 20W-50 oil. When it was passed off to me, I didn't change the oil, I just added it. Would leak 2-3 quarts in a good afternoon, did that for a couple years. Honestly, I'm thinking just as long as you change it, your doing alright with whatever you got! : ),