Subaru's in-house tuning arm STI Japanese market Legacy B4 sedan and its Touring Wagon brethren. limited edition Legacy 2.5GT tS (Subaru talk for Tuned by STI) models with various cosmetic and performance enhancements, but unfortunately, no upgrades to the 2.5-liter flat-four turbo engine.perofrm with new Bilstein suspension, strut tow bars, sport exhaust system, and 18-inch multispoke alloy