My manual says 6 degrees front to back (refrigerator front) and 3 degrees side to side. That is a pretty big range.
Someone posted back a while that they did the calcs for their long bed quad cab truck. The results were it worked out to be about 8" both side to side and front to back difference.
I'm always closer than this when I back for the night, but it's good to know when parking some place for sight seeing.
When traveling down the highway, it doesn't matter as much since the liquids are being jostled around a lot. Though it still bothers me when I'm running 30 minutes up a long uphill.