Or "beer holders" as my mates call them :p
These vehicles are too complex to have a basic curve for reliability. They're a heavy 4x4 vehicle so the costs to maintain them is always going to be higher than for a smaller car. Ongoing costs for my 08 RRS with me doing ALL of the work have been around $1000 per 10,000K including tires, or double what my Audi A4 quattro costs to maintain.
The curve idea might be useful to compare one which has been serviced according to LR's completely inadequate service schedule, versus one which has been serviced by someone who understands mechanical devices. If you service in accordance with LR's schedule, you can realistically expect trans problems before 200K and diff/transfer case failure by 300K. LR worked hard to make the D3/D4/RRS reliable, then stuffed it all up with a laughable (unless you're the owner) service schedule that their dealers unfortunately still take for gospel.
As for the engines, the V8 does seem more reliable, goes like a raped ape and sounds awesome!
But, since I'm always in the TDV6 camp, it's only fair for me to talk about something I know reasonably well - the TDV6 is a great engine - it is reliable and will go WAY beyond 300K, BUT ONLY if it is maintained on time by someone who knows what they're doing. They have a comparatively large number of very simple things that an inept mechanic can easily get wrong.
1. the oil filter has a spigot on it that needs to be located into a little hole in the filter housing, THEN the filter cap screwed down onto it. Mechanics get this wrong by first inserting the filter into the cap (it comes off this way) and screwing them both down onto the housing. The spigot, which is part of the filter's output, doesn't locate into the hole this way, and jams itself against the housing, cutting off oil pressure and (most times) killing the motor. The 3.0 has a redesigned filter that is more intuitive to install.
2. The correct spec oil absolutely must be used. The crank bearings are tabless and are especially reliant on this. Oil service 10-12K km is sufficient. LR has suggested 25K in some markets, which is WAY too long for this engine.
3. The oil pump has the timing belt tensioner mount incorporated into it. On earlier design (pre MY10 models) oil pumps, this mount can fatigue crack and shear off, causing the timing belt to release = dead engine. Most indy mechanics will not change the belt without changing the pump to the latest design too, which is a good mitigation for potential failure. LR dealers however, anticipating a class action I guess, officially do not recognise the problem.
4. Both timing belt tensioners use small diameter bolts that need to be torqued to 24nm - not very tight! It doesn't seem tight enough, which is why some mechanics torque the bolt higher than this just on tuition. This can cause the bolt to fail, releasing the timing belt. For the HPFP belt at least, the engine will survive, but you still have to remove the body to extract the dead bolt.
5. The HPFP on MY07 and later models underwent several revisions before they got it right (november 2010 revision) the earlier versions had issues where diesel could leak onto the turbine housing and start a fire.
6. The turbo can be a problem on 'school run' cars that rarely do much mileage or hard work. Trouble is, the body has to come off to remove it. If you are a contortionist with the strength of a gorilla though, apparently it can be done with the body on.
7. Plastic water outlet has already been mentioned. It develops leaks after 100K and will eventually blow apart under pressure, causing your coolant to disappear rapidly! If you have your music on flat out (which I do quite a lot) you might not notice the little "i>" on the dashboard stating "LOW COOLANT LEVEL"
8. On all the models, make sure you buy one which has had a trans service before 150K. Preferably before 100K! Save yourself learning about trans problems the hard way.
I know this all sounds scary, but you asked for no bs - don't be too deterred - if you're the kind of person who does a lot of mileage and long trips, if you get a TDV6 that has been maintained properly, you'll love it, it's a great little engine with loads of torque, plenty of character, great economy (9.0-9.5 LHK real world for my 08 RRS with road tires and no offroad mods) and reliable if serviced by a meticulous person. As far as capable off-roaders go, I'll go one further and say there are no better diesel engines out there than the LR TDV6/TDV8. My TDV6 suits me because I regularly do long trips and my daily work trip is 55km each way, I do 50,000km+ per year and I am meticulous in doing my own work on it.
If I did a lot of school run style driving, only took it out on trips occasionally and had basic mechanical skills only however, I would definitely get the V8 over the diesel. The diesel doesn't appreciate short trips!
