Let me begin by saying that I really don't care which oil anybody else uses, I know what works for me. The only reason I bothered doing this is to publish my long term results with Amsoil 2 stroke oil. There is a member here that is doing his best to trash a product that works perfectly fine and I just want to put his lame attempts to make a limited test of this product into gospel to rest. The tested piece of equipment is a Stihl FC-75 edger that I purchased in the year 2000. This edger has edged mile after mile of sidewalks and curbs. For the first year that I had this edger in service I used Echo dino oil at 50:1 ratio. I did have problems with oil coming out of the exhaust and plugging the spark arrestor screen. I was also having problems with Shindaiwa T-230 trimmers plugging exhaust ports. So I decided to try the Amsoil 2 stroke oil that my Stihl dealer had. The mix has always been 80:1. Let me say that I have not had a single instance of plugged ports since then. I have used Amsoil is all of my 2 stroke equipment 95% of the time since then. The only exception is the rare (usually the last tank of the year) tankfull of Shaindaiwa ONE mixed at 50:1. I use the Shindy at the end of the year since it comes with fuel stabilizer already mixed in. I first did a compression test. As a control for this test I also have a brand new Stihl FS-80 grass trimmer. I tested the new trimmer with throttle full open, choke off and 10 pulls. It had 120 psi. I then tested the FC-75 edger. The same testing revealed 130 psi. Hmm... There clearly is nothing wrong with the compression. Much to my surprise I found that I still had the screen in the Stihl FC-75 when I partially tore it down this morning. Here are a couple of pics of the screen. It is exactly as it was when I removed it.