[DeleriousZ]

change the oil as often as you like, probably go no more than 3k, i'd go 25-2700 just to be on the safe side... the more you change your oil, as long as you're using the same stuff, it won't hurt your engine, just your wallet. oh, and hopefully your turbo's aren't 'using' any oil.. if they are then you might want to get them checked for leaks.... other than that, it's just increased capacity rather then extra useage

as for the shuddering, my car does it as well, so it's probably nothing to worry about... once it warms up it's all good... same with the transmission.. even when you get a new one it might be a little clunkey before it gets warmed up. most cars do this, so it's pretty normal

ps: wes your avatar is extremely creepy