hey, am new to this but got bit prob, maybe someone has idea...got 1999 classic Impreza, had since february but got FSH, had around 4k spent before i got it, including new,bigger turbo running at 334bhp. Did 420miles last week all on the motorway but cruised at around 80mph...at around the 600mile mak, the day before returned, checked oil and was only showing about 1mm on the dipstick!!!! Filled it to the F mark when cold with Millers 10/60, did the 420 mile return trip, left it 24hours and re-checked...as down to 1mm on the bottom of dipstick!!!!! Got no leaks in engine, left paper under it to see and was nothing there. Got set Defi gauges and no change in oil pressure, temp etc or loss of power. Any ideas cause am scratching my head on this!!!! Oh, it DOESN'T use that same amount of oil where pottering to work, around town etc...