... huge mileages between services...
A little off original topic...
But I would NOT necessarily follow that suggested service period, in respect to oil changes anyway. What follows is not LR specific.
The oil companies, through clever(?) chemistry, reckon they can get oil to stay in grade and stable for much longer than they used to be able to. They sort of have to assume that a handful of variables will be the same for ALL drivers.
They don't include people who only do short journeys and therefore have an increased quantity of moisture & fuel in the engine. Nor do they include people who tow or work hard their engines frequently, people who take their cars to track days, people who drive in extreme cold or hot etc.
Generally we live in a throw away society. If back in the 80's we'd had these new oils and people had treated their 2.5NA's to a 10,000 or longer oil change interval there would not have been many of them still on the road in the late 90's and none in the 00's. That doesn't matter now, you have a fairly cheap engine that will do a job and get scrapped when it fails.
New engines are fairly common now as "replacement parts" it's now not financially viable to repair them even for fairly simple things that in the past would have been a common fix. That also shows a problem with our society, labour has become so expensive at dealers that it's now cheaper to put in a new engine at great environmental waste.
So they now give these service intervals of huge mileages, not because the engines can stay in good health all there life life this, but because they know they can lure people in with these figures but also because if the engine isn't as healthy as it ought to be at 100k then who cares, the original owner is probably long gone. The vehicle can be scrapped or a new engine can be put in and the manufacturer hopefully sells another car or engine.
Also, notice the oil filler cap usually says Castrol, or some oil companies name? Castrol or the oil company in question and the vehicle manufacturer have sat down and thrashed out a deal. Along the lines of we will sell this special oil - last years oil with a new chemical worth 20p in it - which we will claim to be "the oil" for this engine, they sell it to them/us for £16 a litre and tell the owners it's special oil this vehicle MUST have to work on these long service intervals. That is why Castrol oil is the worst muck you can buy, mainly because they spend all their money on having their name stamped into oil filler caps and other expensive marketing not R&D. For that sort of money you could change your oil twice or thrice with a good fully synthetic oil not bearing the Castrol name and still come out better off.
Also, remember that for every mile you drive on oil, that's more deposits circulating round the engine in the oil, I don't know if I want filth that could be 10,000 miles old circulating my engine.
Also, a funny thing is that often they state a high mileage but put, or 1 year, knowing that most vehicles will be back in getting it's oil changed sooner anyway - because they do really need it. Would also probably sort the timing chain wear issues for starters - oh and using a decent oil.
I'll stick to sensible, not wasteful though (the US seem to think 3000 mile oil changes are acceptable) oil change intervals with sensible oil.
