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Which BMW GDI engines used solenoid direct injectors? Is N73 the only BMW engine with solenoid type?

Looks like N74 uses same piezo as N54 N63 S63?

offtopic interesting read: https://automotivetechinfo.com/wp-content/uploads/2021/01/BMW-Fuel-Injectors-Theory-Operation-Diagnosis-Recalls.pdf

N54 uses piezo. N55 (successor), N20 (4 cyl version of N55), and S55 (M3 version of N55, really more like current gen motors) use solenoid. B38/B48/B58/S58 (current gen 3-cyl/4-cyl/6-cyl/"M3") use solenoid too I believe.

I'm not sure about the V8. The manual for the N20 says the N73 uses solenoid, which agrees with what you said.

I would assume, based on this, that first gen BMW DI motors used piezo, but then they moved quickly to solenoid. MINI motors may follow the same trajectory; I think with the release of the B38/B48/B58 motors they are trying much harder to unify their model line behind one set of motors.