I use a lot more of this stuff (isopropyl alcohol) than probably anyone here. In the winter, I use 1 bottle per month and in the summer about 1/3 to 1/2 of a bottle per month. Been doing this for the last 10+ years. Probably 6-8 bottles per year along with a bottle or two of Red Line and or 10-20 ounces of Neutra. Because the Neutra is so much more economical, I’m using more and more of it and haven’t bought the Red Line stuff in a while.
I can’t see how alcohol, which burns very cleanly, could foul a spark plug or some other sensor ... unless it is reacting with other compounds in the fuel. Perhaps causing another additive to precipitate out?
Anyway, my O2 sensor was still fine at 120,000 miles so I can’t imagine I’m doing anything harmful by using this stuff. I figure O2 sensors make good “canaries” in this regard.
If Neutra 131 is an ester (water soluble) as others have suggested on this board, then it should remove at least some of any accumulated moisture. Same with Red Line Complete Fuel System cleaner.
About 6 months ago, my father’s girlfriend’s Honda Prelude developed a nasty hesitation at 4 years old and just over 40,000 miles on the odo. 1 bottle of isopropyl alcohol and Red Line fuel system cleaner and the hesitation cleared up ... and I’m talking within 10 miles.
I suggested she have her fuel filter changed (not in the Honda maintenance schedule for that car) and she traded the car in.
Rick, I don’t see new fuel systems being “tighter” would affect moisture accumulation. Air has to be let into the tank to replace the fuel as it is consumed (or it would create a vacuum) and that air will bring with it moisture … which can accumulate over time. I’m pretty sure control of newer fuel systems is mostly limited to minimizing escaping vapors for emissions (non-tailpipe) and environmental purposes.
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Bror Jace