Looking around a bit, it seems that insolubles includes soot but also other stuff.

If so, it's hard to imagine you'd see numbers like that prior to the EGR delete....unless you're doing entirely highway miles or something. Both my 91 and 92, prior to EGR delete, produced soot at the same rate: 1% every 7,000 miles or so.

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14 E250 Bluetec 4Matic "Sinclair", Palladium Silver on Black, 159k miles
06 E320 CDI "Rutherford", Black on Tan, 179k mi, Stage 1 tune, tuned TCU
91 300D "Otis", Smoke Silver on Tan, 145k mi, wastegate conversion, ALDA delete

19 Honda CR-V EX 77k mi
Fourteen other MB's owned and sold
1961 Very Tolerant Wife