US W124 Diesels:

1987 300D (sedan) and 300TD (wagon) with 6 cylinder 2 valve turbodiesel
1990-1993 300D 2.5 turbo (sedan) with 5 cylinder 2 valve turbodiesel
1995 E300 (sedan) with 6 cylinder 4 valve naturally aspirated Diesel

US W210 Diesels:

1996-1997 E300 (sedan) with 6 cylinder 4 valve naturally aspirated Diesel
1998-1999 E300 (sedan) with 6 cylinder 4 valve turbodiesel

Compared with the turbodiesels, the naturally aspirated engines need to be wound to perform. They'll keep up with modern traffic under 4,000 feet elevation. Any late model minivan gets to 60 mph more quickly than these Diesels except for the 98-99 E300. The rest have to be in top shape to get to 60 mph in 12 seconds. You might beat that Yaris with a good reaction time.

IMO, not ideal for occasional use, not ideal for an occasional driver. That's what Accords and Camrys are for.

IMO, not ideal for performance mods unless you go full bore like they do in Finland. Nothing you do within a reasonable budget will make it perform better than a similar vintage E320, let alone an E420/E430. Comparable V8 gassers are typically cheap, plentiful, better equipped and are available with low miles. As Bill Fisher said about the 1200cc VW engine, fabulous engine when left alone. Disable EGR, ARV, etc., don't even bother with so called free flow air filter.

Sixto
87 300D