rosenfe, fuel filter should be replaced every 60,000 miles. Considering you live in CA I would use Mobil 1 15W50 in a 1995 E320 engine ... per the Owner's Manual the capacity is 7.9 quarts. Best to add 7 quarts, then add oil so the level is midway between the dipstick low and high marks. A suction device is the easiest way to remove used oil (MB dealers suck out used oil) because there is no need to get under the car, but many folks prefer to drain the oil.

The oil filter is a cartridge type that fits inside the black cap (mentioned in other posts).

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Fred Hoelzle