I test driven both the 2016 and 17 back in November when I bought my 2017. on one specific test drive I took both cars on a rather lengthy test down the highway to the next town and back up via the side streets. Having driven one directly after the other I was able to notice a bit less noise (on the highway) with the 2017. This was one of the things (among others) I was specifically paying attention to and did my driving with the radio off just for this reason. And the 2017 I tested had 18" wheels and was a 2.5L while the 2016 had the 16" wheels and was a 2.0L. And even though the larger engine and larger wheels I felt the 2017 was indeed a bit less noisy. It was imo enough to notice and since it even had the larger wheels and engine (which should have made more noise.... it didint and actually sounded a tad better.
But a lot of this in general has to with the car one may be coming from. Its not a quiet vehicle especially when on cement highways. Much much quitter on asphalt highways but so is any car relatively speaking. Overall I find my 2017 less noisy than my 2010 hyundai elantra of which I drove for 150,000 miles so to me its an improvement. But is it less noisy than other new cars? I guess it depends on which car one has.
Many people have mentioned after changing tires they found things less noisy but imo as tires tend to wake up as they wear down it could just simply be a fresh set only sounds better than what the old worn set sounded like. Though some have reported changing tires quickly and noticing a sound sifference so there may be something to it. I will find that out when my time for tire change comes.
Another thing I find somewhat over the top about road noise is that I often think (or ask) what kind of car are we buying here. We are not in a top end car here but are in a compact economy car class. I don't really know what people really expect. This car also imo may be a victim of its own success..lol but here is what I mean. The interior of the 3 is nice and especially with the leatherette and leather. Its simply a nice place to be for a car in this class and feels somewhat elevated for the class. That elevated feeling of comfort and/or pleasantry can work to create a raised level of expectations for quietness. Its quite possible that because we may feel as though sitting in a bit of a higher end vehicle that we then expect the same with noise.
In the end I feel the car does have more noise than I would like it to have while on a cement highway but I also feel its better than my last commuter and is an improvement. So a lot of this is going to come down to what one has been driving prior and also what we should expect from this class of car. If I wanted more quiet I would have bought a higher class of vehicle. something I wouldn't do for my commuter. But I can say one thing for certain, its pleasant to be in this car and even greater to drive it
and it has in many other ways surpassed my expectations for a compact economy class car.