Subaru claims that while this has no bearing on horsepower or torque, it makes the car sound. Meaner and louder. We mentioned to Subaru Also, the sedan STI features two mufflers (still has four pipes) as opposed to the wagon's one giant muffler (and four pipes). However, since there's less weight over the rear wheels (and since the STI's diff is slightly rear biased) they might be a bit slower. Since the sedan is marginally lighter than the five-door, 0-60 mph times might improve. While power is unchanged (305 horsepower and 290 pound-feet of torque), high-speed stability of the four door is greatly improved, as is at the limit handling, by you guessed it that mega wing. The 2011 STI also sports less unsprung weight than the 2010 model due to lighter 18 inch wheels that are a combined 17.6 pounds less heavy. New for the STI(s) this year is an improved suspension consisting of stiffer bushings, stiffer springs, and thicker anti-roll bars at both ends of the car. awkward looking (we know, we know) that the looks are actually improved by a 14 inch wing. Or at least admit that the four door Impreza body is so... And while we love hot little performance wagons, you have to admit the wing is pretty sweet. That's right, you can also buy the five-door STI. This is the first time that Subaru has ever offered an STI in two body styles. For the first time in three years, Subaru is offering up a four-door sedan version of their performance icon, the WRX STI.