It was asked a while back what the numbers were on the Subaru oil pump, during discussion regarding the 23psi bypass pressure setting in the Subaru OE oil filter, as we were trying to figure out why the bypass pressure spec was set so high. So here are the specs on the oil pump, to possibily help understand why the filter bypass rating is set @ 23psi (23.2 actually)

Oil Pump info for 2009 Subaru 2.5 liter four cylinder(identical specs for Turbo DOHC and NA SOHC 2.5 liter motors):


Lubrication Method: Forced lubrication
Pump Type: Trochoid type

Performance (oil temp 80 C which is 176 F)

600rpm: Discharge Pressure 14psi; Discharge rate 4.9 US quarts or more per minute

5000rpm: Discharge pressure 43psi; Discharge rate 49.7 US quarts or more per minute

Relief Valve working pressure: 85psi

Oil Filter

Type: Full Flow
Filtration Area: 124 sq in (800 sq cm)
Bypass Valve opening pressure: 23.2psi
Outer diameter x width: 2.68 x 2.56 in (68 x 65mm)
Installation screw specifications: M 20 x 1.5

Oil Pressure Switch warning light operating pressure: 2.1 psi
Oil Pressure Switch proof pressure: 142 psi


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'09 Subaru Forester .. (Kendall GT-1 Syn Blend 5W30)
'13 Ducati MTS .......... (Silkolene Pro 4 Ester 15W50)