I was looking at driving distance and accuracy, and it doesn't compute... For distance they use 2 holes in opposite directions to offset the wind. For accuracy all holes are used it seems. Looking at these stats all par 4 and 5's are used for possible fairways calculated.
http://www.pgatour.com/r/stats/info/xm.html?101
http://www.pgatour.com/r/stats/info/xm.html?102

So are all clubs off the tee used for accuracy and distance or what? I thought only the driver was used for driving stats.

I believe every Par 4 and 5 is used to compute driving accuracy. However, only 2 holes which players will almost certainly use driver are used for driving distance to ensure they are getting players' longest tee balls.