no, the wheel size are different, so you need new tires. I think otnielarencibia's wheels came with stock cx-9 245/50/20 tires. I got a set of pirelli's, also 245/50/20.
i've been looking to do this "upgrade" as well, but havent been able to found the whole set thats OEM, i can get some knock-offs from ebay but i'd rather not do that, anyone who knows of a set fo cx9 20" wheels for sale, please let me know...
Also, how's the handling and the turning ratio>?