Will this car handle 19 inch rims without suspension modifications?

 

yes. See Wheel-size.com for rim specs. Most post-2010 Volvos use 5x108 wheels with a 63.4 center bore (Volvo uses "hub-centric" wheels so this is important to match). The width and offset (ET mm's) vary a bit by car but from what I see, you can use a 235/40-19 tire on a 8Jx19 ET55 rim. Other S60s use 8.5 and 9" wide rims and adjust the ET slightly but I think the 8x19s work well with 235/40s. (My car has 8x17 with 235/45s as an OEM match)