I installed my summer tires (almost new Euphoria runt flats) a couple of weeks ago and they sure seem squirrley. More than usual! I carefully studied the tires to see if they were marked as unidirectional (with an arrow showing the right way to mount them), but couldn't see anything like that. Although I labelled them when I removed them from the car last Fall, I must have washed the labels off before painting...

Perhaps it's because I have them in the 'wrong' location and they will wear to a little more stable feel, but right now this is a two-hands on the wheel thing

 

I do believe they are. PM Alex the vendor from the Tire Rack, he will know for sure.

 

I was actually wondering the same thing! I put mine on and they are way louder then I remember. I searched high and low, but couldnt find any driectional indication. Im pretty sure they have a tread that is split ^ and V so I don't think they can be, even if they were poorly marked by pirelli.

 

Euphori@s are not unidirectional. Any tire that is directional is conspicuously marked on both sidewalls. I'm still of the belief though once a tire has lived a significant amount of time on one side of the car, it should stay there, rotated from front to back, not side to side.