SWEET!!! Thanks Blown! I'm sure they're brighter but by how much I do not know. Hopefully it says how many lumens it puts out on the back of the aftermarket bulb package.
I'm not too worried about blowing anything up or melting anything with the 55w bulbs. Let's assume that the voltage of the car is 13.8. Here's the math:
Stock
27w / 13.8v = 1.956521739130435 amps per bulb
Aftermarket
55w / 13.8v = 3.985507246376812 amps per bulb
So with stock bulbs we are drawing roughly 4 amps. With 55w bulbs we are drawing roughly 8 amps total. I would assume that there is a 10 amp fuse. If the wiring wasnt able to handle 10 amps, then the fuse could be useless in the event of an overloaded circuit.