[Still Lost]

I've never been good at tire sizes and fitment on any of my cars but I'm thinking about changing the set-up from the stock 19's on my Touareg to something a little more aggressive and custom.

Could I run 295/70's on a 18 for my V10? Would I need to run specific rim offsets?

The tires in consideration are Cooper ST Maxx

Any input would be AWESOME!