I ran 17" Volans on my '96 855R as well as 16" summer tires, and 15" snow tires (I had the car for 11 years)

The 15 and 16 inch tires wore very evenly - the 17" wheels burned up rear tires - good tires.

The car was affected by road irregularities with the wide 17x7s. Kinda like driving a steamroller. It was fine on the highway.

It did handle great with Yokohama Prada spec 2s.

Some years ago, Road & Track tested a BMW with stock 15" wheels, 16, 17, and 18s.

Their track and skid pan tests showed that with the same performance tires, the 15s handled the best!

They opined that most people are pleased with larger wheels because they replace old hard tires with new more expensive ones, the wheels were not a big factor, if not worse.

They asked a BMW engineer to explain their results - his answer - Of course, you must remember that we designed the car for those wheels.

I think that slighter wider performance tires would be a good investment.

Most Volvos do not cotton to much wider tires - my 855R had cut away wheel well liners that had MUCH more room than our other two 850s.