I don't think anyone who works for Amsoil logs into any message boards.
The thing that gets me is that people here and every place end blindly buy oil with no ASTM testing behind it. That's like buying a car without knowing the horsepower and torque it has and buying the car just because you saw many ads for it on TV. That's the wrong reason to buy something.
All of those people using Royal Purple or Red Line would be just as happy or happier with Amsoil. And when you save money with the extended drains with Amsoil (something that Red Line and Royal Purple doesn't do), then you can laugh all the way to the bank.
I use to have a job I was commuting nearly 200 miles per day and I decided to try out the Amsoil 0W30 since this oil is rated to last up to a whopping 35,000 miles (not a typo here for 3,500... that was THIRTY-FIVE THOUSAND miles.)
I decided to give this oil a run for the money and see if it truly performed. I drove an entire 35,000 miles on this oil since I did not want to keep spending money on oil changes every 3 weeks or so. Sure enough, this oil totally lived up to my expectations. My gas mileage increased by a few MPG's and I had ZERO oil consumption in that entire 35,000 miles.
I did however have to change the oil filter mid-way since Amsoil does not have any oil filters that has a full 35,000 miles.
Going that far on the oil was equivalent to 11 oil changes. If Amsoil was good enough to last me a whopping 35,000 miles, I would think going 7,500 to 10,000 for most of the people on here should be perfect.
There's no benefit at all of using Royal Purple over Amsoil. Royal Purple is not going to outperform Amsoil in any way. Plus the fact that Royal Purple costs more money in both the bottle itself and having to change it early.
Fast & Fours magazine did a comparison for many popular oils a long time ago and compared Amsoil to Royal Purple. Amsoil beat Royal Purple.
Synthetic engine / motor oil comparison - Amsoil beats Royal Purple, Mobil 1, Castrol, Hi-Tec, BP, Torco and Shell on the dynometer.
So knowing this, I don't see a reason to use Royal Purple. Where was Royal Purple, Mobil 1 or Red Line back in 1972 when Amsoil was selling synthetic oil? Those companies weren't even wet dreams back then.
I have tried virtually every synthetic oil under the sun over the years. Amsoil has done everything the other oils have done with the ability to go a LOT longer. All the people I know who use Amsoil would never switch to anything else once you get hooked on those 1 year oil changes. Buying Amsoil and changing it every 5,000 miles is foolish. You're simply throwing away your money changing it that early. It doesn't hurt the engine in any way, shape or form going the full 20,000+ miles that it was designed to do... UNLESS you don't have the proper oil filter. If you're using Amsoil and some cheapie Fram or Purolator oil filter, then yeah, you're going to have issues. You'll need to change those cheapie filters often.
My 300 takes an Amsoil EAO38 oil filter. That oil filter is a lot more expensive than the Fram's and Purolators, but it lasts up to 25,000 miles while those cheap filters are only rated for short drains.
I don't know about you guys, but I have a family and a day job. I'm very busy and the last thing I want to be doing is spending time doing oil changes every other month and crap.