Tires: Studde snows on Smart Cars, studded snow tires, smart cars

Question
Barry, I have 2 smart cars.  I would like to mount studded snow tires on the rear for this winter.  I have 4 studded snow tires from a Mercedes I sold a couple years ago and would like to use them.  The smarts call for 175 55R 15.  The snows are 185 65R 15. The smarts are not used for highway trips.  I anticipate if I mount the snows my speedo will be affected.  Studded snows in 17555r15 are spendy, I'm hoping to bypass that expense.. if it's safe.  There appears to be plenty of room in the wheel well, but Smartys are known for their computer issues and I'm sure the tires are connected to the system somehow.  Please let me know if this is something I could do.

Answer
Randy,

It is my understanding that Smart cars are quite peculiar beasts and many of the things you could get away an ordinary car, you can not do with a Smart.

And tires is one of them.

If you'll notice the front and rear tires are not the same size.  Not only that, but the rims are different sizes as well.  This is to prevent someone from trying to change the tire sizes, particularly trying to do the same size front to rear.

A rule of thumb for all cars is that if you put on winter tires, you should put on 4.  If you use studs, you should use studs all around.

Given the peculiarity of the Smart I advise against the move you are considering.