That has to be a typo or a math error.
There's no way a 260E (or 300E 2.6) or 300E or E320 could get that kind of fuel economy.
21.8 I could accept....
2001 E430, Bourdeaux Red, Oyster interior.
1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".