01 Disco with 99k and the dealer suggest Castrol Synthetic Blend. Is it best to use a full synthetic, a blend, or conventional oil? Appreciate any or all input...Thanks!

 

they will all do the job. just do what your wallet will allow. if you go with conventional oil, change it out atleast every 3k miles. im currently on the amsoil every 5k plan. its good stuff and if you join the preferred customer program, their stuff is cheaper than the oil in the stores.

 

I used the Castrol blend for years, it is a great product. The one thing to remember is no mater what you use, you still need to change it every 3000 miles because of how rich the Rover engines run.
Don't forget to use a good filter, like the K&N 3001 or Mobil 1's oil filter.
Mike

 

If you can find the studies on oil types in Motorcycles (very high shear) you'll see that the Mobile-1 when compared to nearly everything (Motul and Amsoil full synthetic should perform similarly) maintained it's viscosity about 3x longer and lost it significantly slower than the other lubricants tested.

The major issue with synthetic isn't that it lasts a long time (which it does, when people say 5K it's more like 8K) but that most don't sludge up when mixed with water and there's a whole lot of water in an engine so when you drain it you tend to get a lot more of it out. (sludge is usually seen as whiteish gunk around the valve cover inside the oil fill hole on most vehicles).

There's never been a test that showed that run properly that it's any more expensive than a 'premium' mineral oil or semi-synthetic. You want to avoid going from one synthetic to another though, find one you can get reliably and stick with it. If you do have to switch run a cheap mineral oil for a few weeks between to be sure to get most of the old synthetic out of the system as the bases don't always mix. You can always mix mineral with synthetic though, so if you get stuck down a litre you can add any full-mineral without worry.

 

I had a loud ticking engine. After addressing the y-pipe gasket leak, my engine was still ticking a bit. I did the ATF treatment followed by 10W40 regular oil. Although it had silenced it even more, I still had an annoying tick while idling, which was even more noticeable at traffic lights between other cars. I decided to get Mobil 1 synthetic in grade 10W30 with a K&N hp 3001 filter, and to my suprise it completely silenced the engine. So I'm now sold on synthetics.

FYI,

Darover

 

It sounds like one of your hydraulic lifters might be marginal. If it had been clogged up the move to Synth might have allowed the new oil to dissolve the old crud in the lifter... I'd like to hear other theories on this, because a sound certainly means something and knowing what it could be can certainly save some other major problem in the future.

 

Well, when it comes to engine technicals, I don't venture in discussions due to my limited knowledge on the subject. So unfortunitely, the only thing I can post is my personal experience and findings. So as I've said, synthetics have completely silenced my engine's ticking. I would think that if the ticking would have beencaused bycrud in a lifter, the ATF treatment would have taken care of this !?!?! right???

In the end, all I can affirm, is that the noise stopped about 250 miles after running with 10W30 Mobil 1 synthetic oil.

 

I've been running synthetics in all my cars since about 9 years ago - before that I used Slick50 and regular oil - some cars tend to leak with synthetics, but LR runs better on it, wether it leaks or not. Our engines are not the most durable out there, Land Rover is not like a good old Mercedes or BMW. I've heard of engine failures on LR at or soon past the 100,000. So with that in mind, I think it would be a good idea to use full synthetic motor oil and a quality filter, and change it at intervals no longer than 5,000 miles. Or, as Mike indicated, even as often as every 3,000. It's cheaper than replacing the engine, and this way you know you've done all that you could to prevent a failure. I also use Lucas fully synthetic oil stabilizer, for what's this worth. I'm not a mechanic, and operate on hype and instinct rather than knowledge, but it's been working for me so far... All my cars have been close to 100,000, some went as far as 200,000 befoure I got rid of them.

 

As for slick 50, do not ever run it, in anything, The teflon can break down causing more damage than the sludge put off by a conventional oil. I run RP, as many know. I put 10W40 in and had a tick, switched to 30 and no problems. I have not done a flush and probably need too.

Point.... I agree with Arsell. Run what you can afford. Synthetics are better, but with the way these run, you can't do extended drains to compensate the price difference. For the money, Mobile 1 is a great oil. Whatever you run, change it......

 

If you are worried about leaks with synthetic oil,
Mobil One synthetic now comes in a Highmileage oil 10w30 and 10w40.
I run it in mine and it helps slow leaks in mine.