Again thanks for you input. Check my link, the Bilstein Q&A is pretty thorough for B2,B4,B6,B8. Somewhat layman-like and obviously for the European (or not U.S.) parts (with U.S. using "comfort", "HD", and "Sport").

Funny, they use the term Bilstein "black" for the B2 & B4 and "yellow" for the B6 & B8. The HD sold here in the US are black. Based on the description I would have thought the B6 = HD based on everything but the color of the shock. On color alone, B4 = HD.

Of course, I did research before purchasing, and of course, was probably sold when I read your link. However, it always comes down to having it installed and then.....

By the way, got the 170 450 (front) and 170 451 (rears). The 450 appear to be sportier version of the 452 for the fronts based on the application for each (sport suspension vs. standard). Whatever. Sachs websites indicate the Super Touring line, in general, are the direct OEM Replacements, better, but not neccesarily any sportier. Again, whatever that means. I prefer technical data versus marketing spiel in these areas.

I get them installed today, and I'll post my impressions for the heck of it.