I know this is an old post. I wanted to make a comment about Seafoam, so I found this thread by googling.
In any event, Seafoam shows up from time to time and is generally strongly recommended by many people.
Curious about what it is, I looked at the MSDS info this evening.
The composition is about half pale oil, about a third naptha (benzine), and about a sixth isopropyl alcohol (rubbing alcohol). I'm having a hard time understanding why this should do anything useful as a gasoline additive. It might absorb water, but straight isopropyl alcohol, or even methanol or ethanol have the ability to do that. None of these components have specific detergent qualities. Pale oil is just .... well.... light colored oil, like 3 in 1. What purpose does this serve except to act as a carrier for the naptha and the isopropyl alcohol? Naptha may already be in your gasoline blend. Its just a common hydrocarbon.
Is the effectiveness of Seafoam just another urban myth?
El Bull -
I'm an ungeneer, not a chemist, but I do sleep a lot in Holiday Inns and other fine hotels...
Seriously, I worked for a number of years on a project involving fuels, learned a little, and am convinced there is something to the old stories regarding a little naptha keeping fuel stable. The petroleums in your regular gasoline are a series of hydrocarbon molecules, ranging from real light ones to sorta heavy ones. Think in terms of a normalized distribution curve like this, with heavier molecules on the left and light ones on the right, while the vertical scale is just a count:
If the peak of the curve is slightly toward having more of the heavier hydrocarbons, you've got diesel fuel. If you've got more hydrocarbons that are slightly lighter, the peak will shift to the right and you have gasoline. (Obviously leaving out additives, alchohol, etc) The problem is that the lighter hydrocarbons are the ones that evaporate, leaving the heavy ones.
Naptha is waaay over to the lighter right end of this curve. That means that if you were to count and plot the hydrocarbon molecules, the curve would have a second little hump off to the right. (No kinkiness there, Tyler) Naptha is a very light hydrocarbon, so it can act as a mild cleaner, but it is still in the range of what the seals and plastics can stand, especially in such small amounts. It also would add to the count of the lighter molecules, which are the ones that evaporate, so the gasoline should remain viable for longer.
They probably added alchohol as an additional cleaner, to help ignition after sitting, and to absorb water. Modern gas has lots of alchohol that wasn't used in fuel when Seafoam was introduced, so I don't see that as a plus anymore. The oil may act as a metals preservative, but I'm not sure. Subjectively, I have less problems with engines that sit when they have been running Seafoam.
As for the other stories about naptha increasing mileage, I remain highly skeptical unless in using harmful quantities.
Checks
