[rondeo]

Diesel fuel pump is driven directly by the exhaust camshaft so it's to the rear on passenger side.

On mine there is a very slow drip from underside of the fuel inlet metering valve.

Inlet metering valve is in the small cylindrical casing just below and to the rear of the pump body.

Easy to eliminate as origin -
It and oil leak can be seen from under the bonnet.

(A narrow beam 3 watt led torch works for me)

Regarding the original post:

If engine oils could be improved that easily why wouldn't oil manufacturers do the same?