I'd like Randy from TT to chime in on any potential interaction with the oil filter first. I don't have any free samples right now.
On a 5HP flathead Briggs WKA "stocker" engine this stuff is said to make peak torque 300-500 RPM sooner in the RPM range and make peak HP 300-500 RPM higher in the RPM range. Temperatures are from 20° to 40° cooler and it makes .2 more horsepower. Randy told me that on a molecular level, the stuff looks like a string. Shortly after running in the engine, the strings get rolled up into little balls and stay that way, acting like tiny ball bearings.
It comes in syringes of 2.5ml for $7 each or $6.50 for 10. Each syringe is good for one oil change in a small engine. A legengds would take a lot more, and probably could be cheaper if it was a larger, single syringe.