Unless you have AWD I would do what AVToller has suggested. For some ridiculous reason I can't find specs on the MZ-02 anywhere online but I am almost positive that it is Q-rated, as is the Graspic DS-1. To me the tread patterns look similar enough so I would pair them up without hesitation. The reason to avoid mismatching tires is because you don't want different characteristics on the front and back of the car. In the most extreme case, suppose you put UHP summer tires on the front and winter tires on the rear. You're doomed - you will understeer right through an intersection in the winter. On the flipside if you put the winters on the front, you'll spin out. What you're talking about it taking a pair of Dunlops and a pair of Bridgestones with similar tread patterns, similar traction characteristics, and similar speed and load ratings. This should not cause you any problems whatsoever. Only thing is that as I said, if you have an AWD car I would think twice.
