mikeCsix

IPA may be more than worthless if it suspends water enough in ethanol free fuel to allow it to "burn" through with the fuel. Water doesn't burn, it turns to a vapor (steam) and may damage engine components like injectors, especially in the direct injection motors. I have seen the results in diesel motors (diesels are direct injection motors), the heat of the flame at the injector coupled with water droplets will damage the finely tuned injector tips destroying the spray pattern, in addition to the reaction of the water and metal in the injectors themselves. What is really needed is a fuel filter/water separator if you have condensation build-up in your fuel tanks. Granted this is more geared to boats and big trucks than sports cars and the use of non-ethanol fuels.

If the ingredients in Seafoam reduce the carbon buildup on the back sides of the valves and inside the cylinders, this may be where the results Phil spoke about earlier. If there is sufficient carbon build up in side the cylinders, compression will increase (unevenly) and would that have a tendency to pull timing at the upper RPM ranges? Carbon buildup on the backsides of the valves would certainly disrupt airflow, but don't know what effect that might have on timing.

Techron is also good at reducing carbon buildup on valves, on another forum I've ready many anecdotes regarding the use of Techron just prior to an oil change and running the engine close to redline for brief moments to beat the carbon off the backsides of the valves - for gas and diesel motors. The caveat is you need to change the oil afterwards to remove the blowby.