UMich does have grade inflation in general, but it depends on the department, level, and course. Be careful: that doesn’t mean it’s better for your GPA compared to a school without grade inflation! The fact that there is no college-wide grade inflation means you may do just as well in two different courses, get A for one, but B for the other! Also, when you apply for positions in places where they’re aware of grade inflation in Michigan, they would consider a B a bad grade, while it might be actually a good grade for the course with tough grading criteria (which is not at all uncommon in departments such as Math and Physics in Michigan).
(btw, if this is about choosing a school, I think you shouldn’t care about this AT ALL!!!)