I recently bought 17-inch Ecopias, but went up to 215/55R17 to get slightly larger diameter. Sidewall indicates maximum cold inflation is 51 psi. I am presently running 48 because 51 seemed a little harsh over bumps. As far as the tire is concerned, there is no issue running the maximum listed on the sidewall with pressure checked at night (early morning) when tire is coldest. The 16-inch Ecopias that came on my 2011 had sidewall maximum of 44 psi cold and that is where I kept them.
Silver LEAF 2011 SL rear ended (totaled) by in-attentive driver 1/4/2015 at 50,422 miles
Silver LEAF 2015 SL purchased 2/7/2015