According to http://felgenkatalog.auto-treff.com
the 285 only came in the single offset and should be shod with 225/45/17. These are a 17x8J wheel.
Having said that, if you look at the size difference in the tyre between a 225/45/17 and 245/40/17 the later is only -0.95% or -6mm smaller in diameter so you could get away with those tyres on.
However for a winter tyre set up they would be great with 225/45/17 winters all round - which is what I run on a set of 158 wheels.