Often times you hear that someone enjoys Pinot Grigio, but does not like Pinot Gris. Or what is the difference between the two. The answer really is quite simple. Although both come from the same type of grape, the styles are regionally different. Pinot Gris which roughly translates to gray pine cone, because of the color of the grape and shape of the cluster, originates in the Alsace region of France. This is a cooler climate and the wine takes on spicy characteristics accompanied by a fuller body. As with other Alsatian varietals the wines can have that tar like petrol flavor with a floral touch. The Alsatian style is what seems to be imitated more often in New World regions such as New Zealand, Australia, Oregon and Washington. In general, if a producer labels the wine as Pinot Gris, more often than not they are intending to replicate the Alsatian style in some form or another.
Pinot Grigio is a term used to describe the varietal produced in Italy. Although they are the same grape, the final product differs immensely because of climate and geographic location. Pinot Grigio tends to be more fruit forward and at times more acidic and lighter bodied. Because of the warmer Mediterranean influence, these grapes tend to be harvested earlier to retain that acidity which contributes to the body of the wine. California is a New World region that more often than not imitates this version of the grape because of its similar climate; in theory.
So in a nut shell, these are the same grapes, but the final product does differ. The only way to find out which team you are on is to try them and make your own conclusion.