Our 2015 Prius Four has the original 15-in wheels but with Kumho tires that were installed by the (non-Toyota) dealer from whom I purchased it. I have not ridden in the back, so I cannot say whether it's noisier in the back than in the front. Today I experienced a 90-minute ride in the back of a 2016 Prius with 17-in wheels ( I didn't check what tires, but it has fewer than 30K miles, so I assume they could be originals). It was noisy -- much too noisy for me to understand easily what those in the front were saying. Is the 2016 model noisier than the 2015 model, or is there more road noise with 17-in wheels because there is a thinner layer of rubber and air between the road and the body of the car, or...?
No direct relationship. Tread pattern & rubber compound are most of it. Inflation pressure, age & wear effects are lesser factors worth mentioning.
However.......the design of the car can have a big impact too. It is hard to gauge that though as experimenting with different year models and different tire brands and sizes on the different models is pretty much impossible for most "normal" owners. Bottom line is: a quiet tire will be quiet no matter what vehicle you put it on. A noisy one will be more noticeable on some vehicles than others. And.......some road surfaces make a LOT of noise no matter what tire or vehicle you have. Thankfully sections of pavement like that seem to be few and far between.
