At the risk of "jumping posts", thought I might give a short reply to the question posed by John Farnworth in the General Purpose 4 Wheel Drive thread. Mention was made of three MF 5600 Series tractors going to the south pole. John F. asked the question if ACGO/MF would need to modify these tractors for the high altitude. John F. also suggested the response might belong in the High Altitude tractors thread. SO, here we go.
I have looked at some websites for information on the engine used in the 5600 tractors. While I didn't find anything specifically stating that it is turbocharged, the fact that it meets T4i emissions indicates it almost certainly is turbocharged. And, on one of the You Tube videos with the hood up, I think I can see the wastegate control.
Assuming then that it is turbocharged, there is your altitude compensation. The turbo, up to a point, can compensate for the thinner altitude air by spinning faster to achieve the desired boost levels. This isn't limitless, of course. The turbo does have a maximum rotor speed limit, and when it reaches that point, most electronically controlled engines will derate fuelling and power slightly to prevent turbo overspeed. For most modern engines, that won't happen except at a combination of extreme high load factor and high altitude - a combination not likely to occur on the trip to the south pole.
I suspect they will be well "winterized" for the trip, with low temperature capable engine coolant, and lighter weight synthetic engine oil.
Any other thoughts or questions about this response, please post away!