Talked to my ChemEng dad yesterday evening briefly about this, and the first thing that he admitted was that his Organic Chemistry chops are atrophied. However, he did admit that the science of adding the resultant acid (either aspirin or ibuprofen) to ethanol gasoline would indeed break the surface tension of the fuel to an extent. So I've decided to experiment until Dan replies:
I dissolved 600 mg of ibuprofen liquigels in both alcohol and peroxide. Happened much faster in the peroxide than in the 99% isopropyl alcohol that I use; the peroxide solution was cloudy like aspirin, but the alcohol solution was not so I presume some sort of reaction happened in the peroxide. Also of note was that there was no particulate that appears to need filtering prior to addition to the gas tank, but I will anyway as a preventative. I've now combined the 2 solutions for filtering prior to use, and will post my results to see if there is an appreciable difference between mileage on aspirin remedy vs ibuprofen remedy. I guess fuel trim data will be useful to an extent as well, so I'll keep an eye on that as well.
Stay tuned, Friends!
UPDATE:
I looked at the jar this morning. A layer of crystals has formed, maybe 1/3rd of the depth of the solution. Shaking the jar broke the layer up but the crystals remain in the solution. Definitely need to filter prior to use. My suspicion is that the reaction between ibuprofen and peroxide lead to this, so I'll try dissolving liquigels in alcohol and then adding peroxide next time to see if the results are the same.
UPDATE 2:
this morning, the morning after yesterday morning's crystal discovery, I added a bit more alcohol to the mixture. So far, 6 hours later, no apparent crystal reformation. Noted for future. Are y'all chomping at your bits to see me run it thru the tank yet? hahaha
MAJOR UPDATE:
I've discovered something about using ibuprofen gelcaps, or possibly one specific brand of them, which could be why Dan was careful and cautious about using them. The big box store brand I've been experimenting with... well, the gel part doesn't seem to want to dissolve so well or easily in alcohol, so I've had to puncture them to get the liquid inside out into the alcohol carrier. A small fork seems to do the trick, once the gelcaps have been swimming in alcohol for a while. What remains is MUCH easier to filter out of the mixture prior to adding the peroxide, which is good news. The better news is that it really seems to work better than aspirin. My mileage has increased fairly significantly with the swap from Aspirin in E10 gas to ibuprofen in E5 gas (midgrade, which I've sourced at a local independent station, at the same price as E10 regular), significantly to me being 15+%, even on winter gas during this warmer early spring weather. I look forward to continued testing as the weather continues to improve, but it seems that the ethanol-busting remedy that's been shared here works quite well when ibuprofen is swapped out for aspirin. And what's best is ibuprofen is available in liquid form, so no more grinding tablets up, and it's easier to make on the road. YMMV, of course.