Car and Driver had a long-tern W210 E320 go 0-60 in 6.8 seconds (detailed in the article where they later had Brabus stick a V-12 in there), so low 7s-high 6s is possible with one.

BTW, the E320 is faster than any US-market W126, especially a 300SEL...Maybe it merely "felt" slower due to the extra refinement and smoothness that a W210 probably has over a W126?

-Sam