i owned a w124 4matic that was a great car - i was able to keep the original 4matic opeartional for 250,000 miles with some effort, but not much cost. That car was sold.

I now own 2 w210 4matics. I'm very happy with both (mileage about 120k and 150k). The 4matics on these works flawlessly without any issues. My gas mileage averages about 5 mpg more than the w124 (I get about 23-25 with mixed city/highway driving).

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07 E350 4Matic wagon, 06 S430 4Matic, 99 SLK 230
retired W210 (x3), W124, W126