I have a lot of experience with Amsoil products. In fact, several of my 911 racer buddies call me “Slick” because of my obsession with the subject.
I use Amsoil in my cars (I don't have it in this 911 at the moment but I will) and have been using it for 6-7 years. It is not snake oil as it has been accused. I have studied it thoroughly, tested and proven the results myself over about 200,000 miles, and there is tons of real world data on the internet that proves it is not snake oil. It is a quality product on par with Mobil-1 and Redline. I have used each of these three products in various cars over the past 20 years and no one of them are ideal for all applications. In the following paragraphs I’ll share a few observations.
Marv posted “I just can't bring myself to trust an oil brand that says leave it in & just add an additive package or bring it back to full when it gets down on the stick.” This is a very valid concern. Amsoil has always marketed their product for “25000 miles or one year” extended drain intervals. While they are the innovators in extended drains, one should not simply put this oil in ones car and “set it and forget it” to steal another popular marketing line. Each car is different and any extended drain interval program should be verified with used oil analysis.
Wayne stated “I agree. There are metallic deposits and debris that are normal wear contaminants in oil. As the oil runs down lower, then it concentrates these contaminants (think of a glass of freshly squeezed orange juice left to evaporate for a day or two - all of the pulp will collect in the bottom).
Refilling the oil solves the low-oil problem, but it doesn't remove the small metallic particles from your engine.” This is true but there are a couple of things to consider. 1) The 10 quart oil system of a 911 is double that of most cars. As such, our systems can handle twice the contaminants as most cars. 2) Most Amsoil products, and the new extended drain Mobil products, have beefed up additive packages to handle the contaminants better than most other oils, synthetic or dino. Frankly, all oils today are much better than the oil companies want us to believe and a 5000 drain interval is safe for most any oil in most any car. I base such comments on years of studying used oil analysis results.
The racing formula that Chris Dillon (Gumba 11) references is a very good oil for track driven 911s and I have friends that have won HSR enduros with that oil in their sumps. However, it is not the best product for street use or street cars that are driven to, then driven on the track, then driven back home. The 20W50 Racing product does have the best combination of bases stocks and anti-wear additives for racing but not the best package for extended drains.
Amsoil markets another high performance 20W50:
that is a better street/track oil, has a better additive package for extended drains, and is quite a bit cheaper (on par with Mobil-1s new extended drain product) than the racing oil. I have run this product in my former 911SC for extended drains and to and from the track with excellent results. I also have several friends, some that frequent this forum, that run this product in their track cars. It is going I my 72 (currently has Mobil-1 in it) the next oil change.
I guess the point of all this is I have the experience and data that confirms that Amsoil products DO perform extremely well. If anyone wants to discuss oil, I’ll be here to chime in.
Don