According to this article "A vehicle that had run for 20,100 km in Example 4 was reassembled with deposits intact. The vehicle run for an additional 1,100 km using the same fuel described in Example 4 but with the addition of the polyetheramine (PEA) from Example 5 at an order of magnitude increased treatment level; that is, an aftermarket treatment level. The concentration of PEA in the treated fuel was 21 ppm by weight of nitrogen and was 3200 ppm by weight on an actives basis. It was also found that intake valve deposits, which are not directly impacted by additive in DISE engines under normal dosages/operating modes, were reduced by 23% by this treatment."
Found it here: http://www.google.com/patents/WO2003078553A2?cl=en
They mention that usually in DI engines valve deposits are not affected by fuel additives but in their test they showed that at higher concentrations it can reduce the deposits. I wonder what concentration of something like Redline SI-1 that translates to?