[ryan_calif]

I heard that Toyota is developing a new "Dynamic Force" engine that supposedly has improved thermal efficiency (and likely better fuel efficiency). Perhaps with Toyota owning part of FHI, Subaru can get in on this, but I don't know how transferrable it will be to the boxer engine layout.

https://newsroom.toyota.co.jp/en/powertrain2018/engine/

 

[RidingWV]

^^^ Regarding the Toyota video - notice that at the 4:12 point, the direct injectors appear to be spraying the intake valves while they are open and down inside the cylinder. Hopefully Subaru is using a similar design on the '19 Forester and carbon buildup on the intake valves will not be a problem. Regardless, we have a 2013 KIA Soul with the 1.6 GDI engine with almost 90K miles and it's still running like new. Synthetic oil reduces fumes and deposits.

As I mentioned earlier, diesel engines for the past 30+ years have used the same basic design principle up to the point of ignition - direct injection not cleaning the intake valves, and pcv fumes being sucked into the intake tract where they deposit on the intake valves. Lots of truck diesels out there with 300K-400K-500K miles still running strong.

.