I don't mean to be rude but if you honestly intend to service the xc yourself and make an adequate job then acquiring Vida/DiCE is your forst step. Also it seems fashonable to use all sorts of sparking plugs in the XC. I have not founk NHK or multi electrose plus work well in Volvo engines. I used them in my Alfa Romeo and they were fine but not Volvo. Don't wait until you have a problem rather get the car's actual service shedule up to date not for the engine only but the gearbox hydralic fluid; transfer box aka angle gear; the prop shaft; differential; viscous coupling/haldex; hubs; brakes & fluid; suspension and stearing. There is plenty to do and no little expense.