I think it's actually 500ml/1000km but either figure is unacceptable.

I've run Mobil1 0w-40 502.00 (which still complies under fixed service interval regime) in the Skoda 1.8tsi & the world still seems to be turning. Without doing a used oil analysis & a tear down of the engine there isn't much more you can claim.

Martin (on this forum) runs Xw-40 & I don't think he left any engine parts trailing down the road.

I think there comes a time when you can drift outside the boundaries slightly & not have any issues.