I use Amsoil everywhere but the atf. I found those prices on their preferred customer site.
75w-90 is what is recommended for the c200. But I have seen other vehicle that will recommend 75w-90 for standard duty, and a higher viscosity like 110 or 140 weight for towing and heavy duty applications.
I was thinking of just going with the 75w-110 because the amsoil site says it offers better protection without affecting mpg. The only thing is I noticed the 75w-140 is strangely cheaper than the 75w-110? So if I can get better protection, even if only slightly better, it is worth it to me.