It's amazing how the oil companies and vehicle manufacturers continue to talk in circles, mis-inform, and generally feed us all full of BS on oil related issues. The power of the internet and boards like this have allowed you and me (the little guy) the ability to get to the bottom of some of these "myths" created to separate us from our $$...but it's not all good...in some cases we end up creating new myths!
Here's a perfect example of double-talk/misinformation:
Harley-Davidson has been making bikes for 101 years and since I can remember, they have touted "their" motor oil that was supposedly "specially created" for their engines. And most people would buy it at $5-6 bucks a quart because that's what the dealer said they should use (only available from your H-D dealer of course!). Well, truth is they just label oil from whomever they get a contract from and market it as their "special" H-D oil - I can't remember but I think it was Sunoco that was the most recent maker. Eventually, there was some testing done outside of Harley which compared their oil to a number of others including Amsoil and Mobil 1 synthetics. Surprise, surprise...the H-D oil was pretty much last in most of the ASTM tests performed. Once word of this test got out, many H-D owners made the switch to Amsoil or Mobil 1 and virtually all of them began getting the benefits of a superior oil. Many of them got a line of BS from the dealers that using synthetic could harm their engine, cause bearing "skate", etc. etc. but there was never any proof of this and I can't remember hearing of one warranty issue...how could you prove it? Well...you will never guess what Harley has come out with just in the past year. That's right, their very own "specially blended" Harley-Davidson synthetic oil - along with lots of claims about how great it is and that you should only be using this synthetic oil for your baby. Oh, and you can only get it at your Harley dealer for about $8/quart!
Bottom line - it's your money....spend it wisely!