I've searched and searched but can not get a straight answer about the m20 injector impedence.

My 89 525i needs new injectors, and I have some 17lb 95 m3 injectors laying around. I know the m3 ones are high impedence, however, I am not sure what the m20 engine uses.

Will the 95 m3 injectors work on this m20?

first we need to know if the injector is either a Saturated Injector or a Peak and Hold Injector

Saturated = average between 12 to 16ohms
Peak and Hold = 2-6 ohms

if both are the same type you are good so far. if your stock ones are saturated make sure the new ones are too. do not put saturated injectors in a peak and hold type PCM circuit. and vice versa

M3 = 17LBS
5er = 15LBS

P2 = (F2/F1)2xP1

p2 = new fuel pressure
p1 = stock fuel pressure
f1 = injectors stock flow rate
f2 = injectors new flow rate

P2 = (15/17)2xP1
P2 = 1.764705xP1
So figure out how much fuel pressure your car has and multiply it by 1.764705
and you can use the new injectors by switching your fuel pressure to P2

Shouldnt the pressure go down with larger injectors instead of up?? Flow rate will be increased even more if the psi is raised.
first we need to know if the injector is either a Saturated Injector or a Peak and Hold Injector

Saturated = average between 12 to 16ohms
Peak and Hold = 2-6 ohms

if both are the same type you are good so far. if your stock ones are saturated make sure the new ones are too. do not put saturated injectors in a peak and hold type PCM circuit. and vice versa

M3 = 17LBS
5er = 15LBS

P2 = (F2/F1)2xP1

p2 = new fuel pressure
p1 = stock fuel pressure
f1 = injectors stock flow rate
f2 = injectors new flow rate

P2 = (15/17)2xP1
P2 = 1.764705xP1
So figure out how much fuel pressure your car has and multiply it by 1.764705
and you can use the new injectors by switching your fuel pressure to P2