i had 19x10.5 +22 on my car, it filled the guards ok, but i was after something more aggressive. youve got to be aware that wide tyres will fill the guard as much as wide wheels, so putting on wide wheels with skinner tyres still wont fill the guards much if you know what i mean. im pretty sure with 19s 275 is about as wide as you can go with out guard work or no sidewall...
i just changed to 18x10.5 +15 and fitted 295 tyres on... looks perfect imo, fills the guards nicely (tucks in slightly at the back towards the top only because im running a couple of degress camber) and the tyres are flush and chunky.
hope that helps..