About PIAA light bulbs

[Jufranpnoy]

Ok I am totally clueless about which bulbs to get for headlights. I checked out www.autodynamic.com to see what headlights they are selling. And am interested in getting PIAAs. I am looking at the Xtreme White Plus and then the Xtreme White. They are the same price but the volts and watts are slightly different...

Xtreme White Plus says...12V 51W = 115W, 4000k

Xtreme White says...12V 55W = 110W, 4150k

What does that actually mean?

[94_AcCoRd_EX]

Please don't cross post. Once is enough.