Sorry - when I referred to the terrain, I meant the roads over a lot of that trip are not what most of us in the Western world really think of as roads-its like driving on trails at times because they are in such a poor and extremely rough and sometimes broken condition, and with other traffic which drives how it likes on whichever side of the road it feels like. Its not funny when you're coming round a bend on a pretty rough mountain road, on what should be"your" side of the road, to find an overloaded 30-ton truck coming the other way directly at you, because the road on the truckers side (if he even cares which side he's on) has partly crumbled away.
Weather erosion and lack of maintenance, together with some very heavy vehicles can wash parts of the road away. Then there's the local driving habits to contend with. In India for example, driving is terrifying. During the day, it can be like driving in a mobile madhouse with vehicles everywhere and NO observable lane or road discipline, and at night, a lot of people - including trucks and buses, don't use lights! Scared the cr*p out of me I can tell you!
Then there's the quality of the fuel to contend with. Let's say it's variable and sometimes - depending on where you are, unobtainable until "the next delivery" which might be a few days!
I don't think from my reading of their blog, that they really experienced any mechanical problems and they brought spares along to perform a service part way through the journey. I would say the engine probably struggled a bit in the mountains - if they were high enough to get altitude sickness (as his wife did) then they were high enough for the engine to get oxygen starved!
The thing is, most people who do this trip, do it in fully expedition-kitted out Land Rovers and Land Cruisers, not in a little KJ with a service before it sets off, a jerry can for spare fuel, and a set of the spares you need to perform a service en-route. Proof indeed for all those who think "Mall crawler"
