Horizontally opposed engine
Horizontally opposed engine configurations are efficient in lower weight distribution, but, inherently not durable for longevity or fuel efficiency. Inline configurations much more durable and I hope to see Subaru change in that regard and more influence from Toyota may contribute. Also agree with comments that a boosted engine requires dedicated reinforcing of critical engine components to withstand the pressures regardless of configuration. Reliability of BMW & Toyota inline engines are legendary to name but a few. Cheers