Question:  Are studded tires legal in Michigan ?
Answer:  In practical terms, no.   
MCL 257.710  allows for the use of studded tires if they meet the specifications listed in subparts (c), (d), and (e).  The part that specifically deals with studded tires is subpart (d) which states; "The department of state highways and transportation shall promulgate rules establishing acceptable standards to permit the use of a tire with studs or other traction devices to be used on a street or highway after April 1, 1975. The rules shall make separate provision for the extreme winter snow and ice conditions of the Upper Peninsula and the Northern Lower Peninsula. The rules shall include a restriction on the amount and dimension of protrusions that may be allowed on a tire, the type of material that may be used in a stud, traction device, or tire, and the amount of road wear that a tire with studs or other traction devices may cause on a street or highway."
Administrative Rules 247.171 through 247.175 govern studded tires and set the criteria for their use.
These rules state two conditions that must be met for the use of studded tires. Note: to date no manufacturer of tire studs has supplied information to the Michigan Department of Transportation that their product meets or exceeds the required pavement wear specifications.
First, they can only be used between November 15 and April 1 of the succeeding year except in the Upper Peninsula and the Northern Lower Peninsula , where, because of extreme winter snow and ice conditions, they may be used between October 1 and May 1of the succeeding year.  Northern Lower Peninsula is defined as those counties whose southern boundaries are as far or farther north than the southern boundary of Missaukee county.
Second, studs or other traction devices shall not be used unless they wear either concrete or asphalt pavements, typical of those in this state, at a rate not to exceed 25% of the reference standard studded tire.