wheels/Tires Question

Finally i got 2 wheels for the rear. it's from CLK55
they are 17x8.5 i don't really know that much about tires. but wut kind of tires i should get??????
245/40/17???? or ?????
Help Please
)..fwiw, oem on our 96 model was bridgestone expedia s01, which we still have on the 3 17x7.5 rims
.. i know i know, 13 year old rubber


