Stock 2010 (Mfgr date 11/09) XC60 3.0 T6 AWD, approaching 100K miles, looking to take the ride to 150K. As a result, planning to install Bilstein B6 struts/dampers (long overdue), replace bushings/mounts front-to-back where/if needed and grab some new rubber. Doing nothing else other than basic maintenance on what has been a well-maintained ride.

I’m no stranger to wheel-set and tire-size mods on various vehicles (4-wheelers, roadsters, etc.) and am using all the typical calculators available re: fitment but thought I’d ask you folks here with more real-world experience. This car belongs to the lady of the house so its been “all stock, all OEM, all the time” and with respect to rubber, we’ve only ran spec 235/60-18 rubber on the original wheels to-date. If I should stick to that, will do, works fine but…I’m looking to get a little more section width under the car and be able to run a specific brand/tire of choice if I can without impact.

- Wheel-set: Not open to after-market wheels, sticking with the stock 7.5J x 18 ET55
- Current tire: 235/60-18
- Desired tire: 255/55-18 (specs are virtually identical to the 235/60 as you know except for the added ~3/4” section width

I was underneath doing another scheduled oil change yesterday and measured, re-measured and measured some more (front and back) and I’m still uncertain, wanted to cross-check here. Any issues? If I need to / should stay with OEM sizes I’m good with that, have options. Thanks in advance.

FYI – I did hit the archives here and elsewhere and will continue to search but…if anyone can confirm from experience that would be appreciated.

 

start by checking out wheel-size.com to get the standard wheel specs including rim width and offset. If you find a bigger cross section on another size rim, you should be good to go. Once you have that, you can take your measurements to know how much wider a tire/rim the car will accomodate. adding 20mm to tire width (as noted .8") will mean you need about a half inch clearance on the inside and half inch clearance on the outside. If you have less on one side versus the other you need to correct via the rim's offset. I'd start by measuring the outside first with the car on the ground doing some lock to lock turns. curious if the rims will bolt up with some form of a spacer (measuring not for driving).

 

Input appreciated, thanks.