So, first long drive on a new to me two tank '82 Benz 240D. Drove OK
in the week leading up to a big drive, not so good during the big
drive:

Night 1: 260 miles, Warm up on diesel & balance of trip on WVO (No
bubbles in pan test, filtered through nominal 5 micron sock filters).
60-75 MPH the whole way, smelled like oil at the toll booth. Switched
to diesel, last 20 miles, cause I thought WVO was running out (Pointed
uphill, got a little hesitation)

Day 2: Checked WVO, <1/2" left in the tank. ~100 miles on diesel.
Noticed oil pressure gage, usually pegged at '3' now floating between
low to mid '2'. Engine rattle at idle goes away at higher revs as oil
pressure increases, began to notice hesitation when it points uphill,
otherwise runs OK.

Day 3: Checked oil, bottom of the stick. 2.5 quarts brings it to top
of stick. Drive 50 miles, bottom of stick again. 1.5 quarts brings it .
5 quart above top of stick. 1 quart is used over next 250 miles, but
oil pressure stays pegged at '3'. Over last 100 miles loss of power
worsens to 55mph level with pedal floored.

Day 4: Volvo goes to work. Check oil on the benz, note 1 quart used /
250 mi. Check coolant, hope not to see oil. Maybe 2-3 quarts of green,
rust and dark grey crud come out. No oil floating on top. NEVER saw
the temp get above 80 C.

I think the power loss, especially with the car pointing uphill is an
airbound fuel filter (the little one) due to a clogged large filter-
if the IP pulls a vacuum, the little one will fill w/ air.

As for the oil and coolant loss, I'm hoping it's 'just' a head gasket.

Any suggestions, including leaving it on the bad side of town?

Andy