Land Rover’s oil spec is recommended. If you’re under the Service program, then JLR will handle it. But I am going to bet the original spec oil is not what they’re putting in. The reason they may specify an oil that only a JLR dealership typically has, is because that’s where they want you to have it serviced. The income from that is part of what makes a dealership continue to exist. Often the income from sales pales in comparison. (When compared against wholesale costs.)

As for the argument of siphoning oil versus draining; a friend of mine who drives tens of thousands of miles professionally on a regular basis, has to change his oil every few months so for that, he siphons it but once a year he drains it just to make sure there’s very little sediment in the bottom of the oil pan.

Oil specs are constantly improved upon, and you’ll see the phrase “meets or exceeds” all the time. That means the newer oil is ‘better’ as long as it’s the correct type & weight for your situation vehicle and model. (And your location, different parts of the world have different specs.)

So don’t just assume what somebody uploads on a site like this or post pictures of online is what you should have! Your best bet if you don’t have the owner’s literature that came with the vehicle is to go online to JLR TOPIX. Create a login using your VIN and they will match the correct literature for owners to your vehicle exactly.

Because just like you wouldn’t want to use gasoline that’s been in your tank for several years. You wouldn’t want oil that was manufactured the same time your vehicle was.

And I guarantee those who act like they know it all and profess that they’re getting the exact spec in the manual even when their vehicle is approaching a decade in age… they’re not! They're just being told so to pacify them.