During my last 2 services of my 2009 XF PL, I had 2010 and 2011 XF P loaners. In both cases, the ride was much smoother than mine. I did notice that in both cases, the loaners had ContiProContact tires versus my Pirelli's but wonder if there are any other changes i.e. shocks, springs, etc.?

I'm thinking of changing to the ContiProContact's when the Pirelli's go but would also want to make any other changes at the same time. Any suggestions?