if they have stud holes factory then you can not stud them once they have seen road use the studs will just come out when you are driving.
WRONG.
they require a certain tread depth.
I worked at a tire shop and that was not the case.
siping is much better then studs and costs the same amount.
dropping pressure will help tremendously. 3-5psi is alot. if you run 35... i recommend dropping to 28psi
that or chain up!