I just bought a 2003 WRX with a 5 speed and 70,000 miles. I just had some general questions about the car that I had developed over the past 10 days since I bought it and have spent some time with it. First off, boost, my gauge reads to .15, but I never seen it boost past .1. Is that normal? The motor calls for 5w30 oil, but the dealer recommened synthetic 0w-40 Mobil One. I run in hot and cold conditions, what would anyone recomend for the mileage I have? I had owned one other manuel before, it was a 92 f 150 with a supercharged 5.0. When I shift my WRX, anytime my rpms are above 2000, when the clutch is disengaged, there is a 500 rpm jump, my old truck never did that. Is that common as well? What octane should I run? Would additives be a good idea? No racing, just everyday driving... any ideas how to increase fuel mileage without losing power? Thanks, any help would be much appreciated.