Oil capacity of a 2.5 tdi nissan np300

Check this site for your exact model. You need the engine code to get the litre capacity of the oil.

http://cararac.com/engine_oil/nissan/vanette.html

most small engines have a sump capacity of 4 litres (convert that if in USA) with about 1/2 litre for the oil filter

With or without a filter? Have you lost the dipstick? Fill it to the full mark, about 6 liters without filter, plus 1 litre to fill the oil filter. Run engine then check levels again. Try not to overfill the sump.

with a filter its a nudge over 4 litres but you do have a dip stick to check it with

Oil Capacity (Approximate)

DRAIN AND REFILL

With Oil Filter 3.5 l (3 3/4 US.qt, 3 3/8 Imp.qt)
Without Oil Filter 3.3 l (3 1/2 US.qt, 2 7/8 Imp.qt)
DRY ENGINE (engine overhaul) 4.1 l (4 3/8 US.qt, 3 5/8 Imp.qt)

CAPACITIES
Engine, 2WDwithout filter..........3.5 quarts[1]
Engine, 4WDwithout filter..........4.0 quarts[1]
Cooling System, Initial Fill..........8.5 quarts
AMSOIL Antifreeze and Engine Coolant
Automatic Transmission, Total Fill..........7.4 quarts
Manual Transmission, 2WD..........4.2 pints
Manual Transmission, 4WD..........8.4 pints
Differential, 2WD Rear..........3.2 pints
Differential, 4WD Rear..........2.7 pints
Differential, Front..........2.7 pints
Transfer Case,..........4.6 pints

1. Add extra oil when replacing filter.
refill check oil level.

TORQUES
Oil Drain Plug.....22-29 ft-lbs
Transfer case
Fill Plug.....18-25 ft-lbs
Drain Plug.....18-25 ft-lbs
Manual Transmission
Fill Plug.....18-25 ft-lbs
Drain Plug.....18-25 ft-lbs

Fuel tank, 17.2 gallons. Radiator capacity, 1.25 gallons. Oil capacity 4.5 quarts with the filter. Oil pressure, 20-50 psi.

Including filter; the oil capacity for a 2WD, 2000, Nissan, Frontier, 4cyl (Ka24de) is 3-3/4 quarts. Straight out of the Haynes manual.

owner's manual states the engine takes 2 7/8 quarts with a filter change.