Here is a little more info from Chevron on Techron.
First, a little history….
When fuel injection moved downstream from the top of the intake manifold into the intake ports, the industry immediately had problems with injector fouling. What happens is that every time the engine is shut down, a droplet of fuel hanging from the injector tip evaporates, leaving behind residue that interferes with the injector pattern. Mobil, to their credit, stepped up to the challenge by increasing their detergent levels in their gasolines by almost threefold. This took care of the injector issue, but moved the deposits downstream onto the intake valves. Further research showed that certain additives could clean valves as well, but then the deposits moved downstream to the combustion chambers and piston crowns, raising compression, octane requirement, and even causing mechanical interference in the engine. The Techron system (I had the pleasure to test these additives in my Amoco days) was the first full deposit control additive system that will not only minimize all three deposits, but clean them up as well.
The other benefits of the polyetheramine (PEA) compared to competitors' polybutenamine (PBA) and other detergents are the following:
PEA's can prevent sulfate deposits that occur in fuel sending units due to high sulfur content in today's fuels. Fuel quality has not improved, and more customers are "shopping" their fuels today, so fuel standards aren't what they used to be. Plus, as Merritt said, the additive treat levels have been quite relaxed in recent years.
PEA's will work in oxygenated fuels (E-10, E-85, etc). Other additives, including PBA's, have had issues with solubility in these blends, and form gummy deposits that can plug injectors and contribute to deposits. Also, some of the ethanol and other alcohols are not as high a quality as hoped for, and also are high in sulfur and chloride content. These can form salts on fuel sending units as well, and plug filters in fuel injection systems. The PEA's handle these deposits nicely.