sunday times recommended buy, page-17

Yes Chris, I don't see a problem. Friend of mine works at Grasberg and apart from the temperature, he's fine.
He's in charge of the Trak Indo hire fleet and he reckons the modern day engines breathe OK up there. Obviously there is some loss of performance and reduced time periods between oil changes, (due to fuel dilution). Engine life for the Caterpillar engines, (designed specifically for high altitudes) is around 13000 hours as compared to the normal 16000 hrs at sea level.
But they're working.............and making millions.