Just looked at the STP website (www.stp.com
It is a nice website, but I noticed two things:
1. In the FAQ:
"Are STP® products safe for two-cycle engines? four-cycle engines?
STP® oil and fuel additives have been specifically formulated for use in four-cycle, gasoline engines. Extensive testing in these engines has covered a broad range of passenger car usage and has clearly demonstrated the value of our products in these applications. However, we have not evaluated the performance of our products in two-cycle engines. Therefore, we do not currently recommend that they be used for two-cycle applications"
If you read carefully, they do not answer their own question.
All they say is testing has clearly demonstrated value in the applications. It does in no way state there have been no issues. I wonder why...
2. In some of their product descriptions it says as a positive thing that the stuff is made from Jet Fuel. If that means normal aviation jet fuel, that is some of the worst stuff imaginable for a car engine.
Have you ever looked at the engine cowls of a turboprop aircraft? Have you noticed the soot? That is jet fuel for you. Jet fuel is basically kerosene of the lowest quality. It is all about making a fuel cheap enough to burn by the tons. An airliner uses about one ton per 100 km. (Aviators please correct this if not correct.)
STP say they "use no corosive chemicals such as alcohol in their products". Since when is alcohol corosive? You americans of the mid-west drive on about 30% alcohol when you fill the car up. That is how corrosive alcohol is to car engines.
(Anyone who remembers that US petrol is corrosive to Nikasil alloy used in certain engines from BMW and Porsche among others, should know that it is the high sulfur content of certain US petrols that is the problem, not the alcohol content.)
Anyway, although their marketing is not absolutely convincing, I doubt that a few drops of jet fuel would cause any problem when mixed with a tank of petrol, so if everone here thinks STP FSC is a good idea I might very well give a try.