I drive my STi on a daily basis, i don't drive it too hard but it does see the occastional 6KRPM. Lately I've noticed at high RPM's the engine feels (for lack of a better word) "unstable". Basically the engine feels like it's pushing a lot harder, but the car feels slower! We've been getting pretty cold temperatures here (0-5 degrees C consistantly) and i've changed to my snowtires. Would this have anything to do w/ the car acting different? The car is still a baby with about 6000km on it and i always feed it 94 Octane. Don't know what the problem could be. Does anyone else feel this, or felt this at one time?