gxsr - both materials are black, viton is more fuel resistant. Mine went about 2 months after the ULSD change over although i had also burned a fair amount of B99 too. I've been switching everything over slowly ever since.

Your pdf isnt dated BTW. M.B.Doc posted the other pdf in response to specific questions I asked him prior to doing my DV seals. HE claimed his pdf was the most current revision at that itme.

I'm not certain it makes that much difference and in fact did not follow the 35nm one time only procedure exactly when I did mine.

__________________
Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)