IAG V3 AOS Install on a BRAND NEW Subaru WRX!! IN DEPTH!! 

Obviously ;)

What grill is this on your car Brandon??

How do you know?

@@ubroberts5541 I've used them on a GTI to keep the intake valves clean. But they do little or nothing in preventing build up on intake valves.

I usually keep a vehicle 10 years+ and I’ve seen issues were we had a turbo compressor drop efficiency 8% in the test cell due to oil fouling. That goes into the intercooler too. The bigger issue is direct injection. Gas engines must mix air and fuel COMPLETELY before combustion. This is super easy to do on a port injected engine because you start injecting when the intake valve opens. With direct injection you have to inject well before BDC on the intake stroke to mix the fuel. No fuel washes down the intake valves on direct injection. Worse , all direct injection engines are challenged to mix and ultimately they are a little sootier than port burn. This is why the oil volume in the pan is 25% more on a DI engine. The advantages of DI is efficiency and response but the fouling of the intake valves and the rings can get ugly on a high power high reving engine. Hence the need for separation of oil from crankcase gases. Bottom line is you dont want oil fouling your turbo and TMIC. And you don’t want oil in your intake. Subie isn’t going to see failures in 3yrs/36k so they skip the AOS due to cost. But long term the oil coming in will require you to raise octane as the oil changes the burn rate. Turbo direct injection high speed high power engines will last longer with a breather. The first DI engines that Chevy made in 2013 (Equinox) didn’t have good mixing and every one of them suddenly went to using a quart per 1000miles. My colleague had Chevy replace his power cylinder for free at 100,000 miles with a new design that didn’t foul.