PS tests seek out best overall gasoline and diesel additives.
If we used our boats like the family car, back and forth to work each day, fuel would never sit for more than a few weeks and it would never age. Instead, boats sit for weeks at a time in-season, and for months during the off-season. Water, oxygen, bacteria, metal ions, and even instabilities in the molecules themselves combine to turn fresh fuel into a soup that will clog filters, corrode fuel systems, and leave us stranded. Fuel refineries have long known this, and all products are dosed with inhibitors at the refinery; however, these dosages are calculated for the normal distribution and storage times, not half-full tanks that will sit for months or even years.