I am contemplating purchasing a back-up set of wheels for my 996tt. I have hollows. I will not be tracking the car.

What are the differences between these two wheel types other than the obvious?

The hollows seem to be the preffered choice on this forum, why?

Can wheel types be mixed, on the same axel, or front to back.

Thanks for your response(s)

 

and how can you visually tell the difference between hollow and solid?

 

Weight is the primary difference between the two. The hollows are (obviously) lighter. For that reason, I wouldn't suggest mixing them. To tell the difference, hollow wheels are smooth on the inside face, whereas solids have a groove pattern.