Saw that thread, participated in that thread. Best is a qualitative measure. Biosyn has proved to be better at managing fuel dilution, but has not been proved to provide the same level of film strength as Amsoil, and no other oil RAT has tested bests Amsoil Signature Series for film strength.

I will take film strength over fuel dilution control any day. Fuel dilution is easily managed with OCI. There is no mitigation for lack of film strength.

 

Wait. Despite being puzzled beyond words, have I found a fellow Amsoil Friend here?

If so, please explain or reach out to me. I'm a Preferred Member NOT looking to sell ANYTHING whatsoever. Just wish to hear what you have to say buddy! I have yet to do any oil change!

 

One acronym, BITOG.

 

I give up.......

Edit. Ok. I got it.

 

What used to be a great resource, now cluttered with amateur tribologists and a wealth of bad information with just enough glimmer of jewels of wisdom to make it all seem OK. Seems to happen to lots of Internet forums.

 

I don't agree with Amsoil's change interval recommendations. Oils suspend metal wear particles. Changing the oil removes those particles and reduces the abrasiveness of the lubricant. Modern engines are truly marvels of engineering because a modern engine will tolerate a whole lot more abuse than the engines of 20 - 30 - 40 years ago. So, you could quite literally choose not to change your oil and only keep it topped off and still have a running engine at 100k miles. That was impossible in days of yore. It also doesn't make it the most prudent path forward depending on your goals. If you are leasing the car and have no intention of keeping it after the lease, use the cheapest oil at the longest OCI and save your pennies for the next car you wish to abuse. If you plan to keep the car for an extended period and would like it to remain reliable, use a better oil and OCI closer to factory recommendations. If you plan to keep your car and drive it hard - track days, etc., and don't want to spend valuable dollars on engine work, buy the best oils and stick rigidly to the factory's recommendations. It really all comes down to how long you intend to keep your car and how long you want to go between major rebuilds AND make the best possible power.

Added bonus for Amsoil Signature, or any of RAT's top rated oils - should you lose oil pressure for some reason, the remaining film strength of the oil you chose suddenly becomes critical to ensuring the engine is not permanently damaged.

I do not run Amsoil in my cars. I run Mobil 1. It provides a very high film strength (not nearly as high as Amsoil's), is available at almost any Wal-Mart, and costs less than half what the same amount of Amsoil Signature series oil costs. Because I do regular analysis of the oil I run (yes, I use Blackstone knowing full well they are not a leader in this space, but any analysis beats NO analysis), I have great confidence my engines will continue to run just fine for a long time and will continue to make good power as long as I care to run them. But I'm also the guy who rebuilt his first engine in 1973 when I was 13 years old under the tutelage of my father who has been building street and competition engines professionally since before I was born.

So - I respect Amsoil for what it is: a superior product at a premium price.

 

Well said "Senior Moderator." Especially the "Blackstone" part which I use on my Cummins!

Oh- exactly which Mobil 1 product do you use, and I assume your OCI is the 7500 mark?

 

I use the standard 5w-30 Mobil 1 Advanced Synthetic in the gray bottle. I tried EP and didn't like what I saw in the analysis and didn't like what I saw about EP on RAT's site. The IS has been on extended changes mostly around 10k to 12k miles. The wife's GS F is getting changed at the factory intervals to ensure good resale value by creating a log of the engine's wear history. The iron and copper numbers it is producing are stellar and are posted in the GS F forum. My assumption is, at the factory interval, fuel dilution as provided by the factory tune is not a big issue. In the IS with the much longer intervals, yes, in all likelihood fuel dilution is a serious problem. After having a reliable test done for this, I have reduced the IS intervals to 6k miles.

I want to send the RLI oil to RAT for testing. If the Biosyn oil tests well, it might become my new favorite, but one thing will keep me on Mobil 1 - availability. RLI might make a great product, but the challenge of having it on hand and reasonably fresh isn't small. Mobil 1 is so widely available I have no concerns about taking a long trip and if for some unusual reason I need to add oil, I will be able to find it quickly. This scenario happened to me with my Supra. I have run Red Line in it forever, and had a situation where the level got low enough for the low level light to come on very far from any source of Red Line oil. I added a quart of Mobil 1 after talking to both Red Line and Mobil about it. I wasn't happy. I still run Red Line in the Supra, but it's not a daily any more so it's not such a big deal.

 

 

Thanks for pointing this fact out, I never really noticed the O-Rings before to be honest. Tell me JT - Which Amsoil Product did you use? I just hit 5k on my F which still has the two "Complimentary Oil Changes" waiting. After my 2nd one is done I intend on using the Amsoil "Signature Series" fluid, and now - their Filters as well. Thanks again!

 

I went with signature series 5w-30. I switched to Mobil 1 during my last oil change at ~7000 miles, and now amsoil at 10K miles. Next change will probably be around this time next year!