C'mon, the 190 series (W201) has been introduced *after* the R107. The original wonky numbering system is on the W111 between 1959 and 1968 with a single outlier in the "280 SE 3.5" instead of "350 SE" as you would expect from the other model numbers (220/230/250/280 all being roughly 1/10 of the displacement). Afterwards between 1965 and 1972 the W108/W109 series came which *sometimes* had 1/10th of it's displacement in the moniker, but *sometimes* "280 SE" or "300 SEL" with the displacement (3.5, 4.5 or 6.3) only added to the end...

Then again, the BMW E46 line was all over the place as well: 316i with 1.6, 1.8 or 1.9 litres, 318i with 1.9 or 2.0 litres, 320i with 2.0 or 2.2 litres, 323i and 325i with both 2.5 litres and 318d with two *different* 2.0 litre-engines...