Firstly, each engine is different, piston clearance can vary, so crankcase pressure is different.

Secondly, pcv constantly sucks oil vapour out of crank breather. When I took off throttle body, I can see a small oil puddle near the pcv nipple.

Thirdly, when I had my catch can, I stuffed it with two stroke engine air filter, it catch very little amount of oil.

Breather wont spill oil every where, oil comea out as vapour. I find different oil have very different blowby characteristics.

Bit it is illegal, but for the sake of the engine. I prefer breather. ARC catch can with breather is very popular on GTRs.

using the Perth-WRX mobile app

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MY08 STI 422whp at 1.5bar on E85, built by Diversion Garage, assembled and tuned by EvoR

Update from new owner: 375whp at 1.4bar on 98, at Tokyo Motorsport