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Im off the Rotella diesel oil bandwagon. Going by the books and keeping it simple this time. Castrol GTX High Mileage 10W-40 with 3k oil changes. I may use ZDDP Plus additive.
Castrol has been a long time partner with Land Rover and I trust that all engine development was properly tested using Castrol lubricants. As old as the Rover V8 is surly LR knows best when it comes to lubricants and service.
Extensive reading up on ZDDP has lead me to this interesting article which suggests that using a diesel oil for the sake of the ZDDP may NOT be advisable.
"....ZDDP is a multifunctional additive; it has powerful antioxidant effect in addition to the antiwear characteristics. The size and type of the alkyl group attached to the Thio phosphate within the molecule influences the relative antiwear antioxidant balance of ZDDP additive. Over time Castrol have used modified ZDDP’s that are more intended for wear performance and substituted other materials to boost antioxidant performance of our engine oils. So looking at Zinc and/or Phosphorus levels alone does not tell the full story in terms of wear protection.
The majority of the Castrol passenger car lubricants sold in Australia are ACEA qualified as well as API qualified. The ACEA requires extra valve train wear, VTW, tests over and above API requirements. In addition most of Castrol ACEA qualified products are 0.10% Phosphorus maximum. The same as we have used for 20 years or more. So that is why some of our ACEA qualified oils only claim API SL even though they pass all API SM engine performance requirements, the Phosphorus content is above the maximum level allowed for ILSAC grades.
There has been discussion about using diesel engine oils instead of passenger car engine oils. Some of these do currently contain higher levels of Phosphorus, ZDDP, than passenger car qualified to API SL or SM. They have higher Phosphorus to help minimise soot related wear. Future generations of these oils will also have Phosphorus limits and be lower over time for the same reasons as for passenger car engine oils.
The higher level of Phosphorus is not a guarantee of satisfactory wear protection. As I said earlier, wear performance is related to the particular ZDDP being used. Also many of the diesel oils with higher Phosphorus also contain higher levels of detergent and dispersant which compete for surface area with the ZDDP which can reduce its effectiveness. During the development of the current API SM engine tests, a high phosphorus diesel engine oil was run in a flat tappet, push rod engine test and it failed the wear requirements with worse results than most low Phosphorus passenger car oils.
In Australia we have many people rebuilding older vehicles and engines. Many of these people choose to put a modified cam into the engine when it is rebuilt. That is often the case even though they do not plan to get involved with Motorsport and the engine spends most of it life at low RPM. Modified cams with higher lift often require stronger or dual valve springs. All of these modifications increase load on the valve train and increase the likelihood of wear on cams and tappets.
The first few minutes of operation for new cam and tappets are very important. Run-in is important for good long service life. Castrol have put considerable effort into understanding valve train lubrication. Research has shown one of the highest if not highest wear mode for a cam and tappets is while the engine is at idle. Running an engine at medium speed, say 2,000 to 4,000 rpm generates much less metal-to-metal contact between cam and tappet than at engine idle.
Also ZDDP is temperature activated so running the engine at low oil temperature also accelerates cam and tappet wear. Some years ago a race team contacted us after wearing out three camshafts during run-in on a dyno. They ran the oil at approx. 50°C. We recommended take the oil to 85°C, no more cam wear issues...."
Using a bottle of ZDDP additive with Land Rover recommend engine oil might be an alternative solution. However I need to do more research on bottled additives before I use this product in my truck. Some articles say its totally safe to add bottled additives and others suggest "adding ZDDP may not actually go into the suspension with the oil, ending up as a sludge...".
"....Castrol EDGE SAE 5W-50 has been recently reformulated to have a boosted level of ZDDP (1250 ppm) to help protect flat tappet cam engines in classic cars. This engine oil is a full synthetic, has excellent cold temperature properties, and has a high temperature viscosity (SAE 50) that is suitable for use in many classic car applications.
Thank you again for contacting Castrol, we value your patronage!
The two top indy shops around here are putting 20w50 standard (non synth) in all the trucks they service now. One Swepco and the other Lubro Molly, FWIW.
Remember not to break one of these in with synthetic, rings won't seal.
Otherwise I can't complain about the Rotella 15w40.
I've been using the Shell Semi senthetic T5 Rotella 15w-40 since around 2012 in my 03. Located in Denver. I add a 1/2 quart of Lucus stop leak and Proline oil each oil change. Runs like a top. Maybe I got one where they tightened all the bolts to the magical torque settings. I have a 154k on original heads.
I've been using Castrol 10W-40 ever since I started with LRs. The high mileage is a synthetic blend and is usually the same price as the conventional so I like to use that. Good choice.
I've been using the Shell Semi senthetic T5 Rotella 15w-40 since around 2012 in my 03. Located in Denver. I add a 1/2 quart of Lucus stop leak and Proline oil each oil change. Runs like a top. Maybe I got one where they tightened all the bolts to the magical torque settings. I have a 154k on original heads.
All the same here 04', minus the stop leak. But maybe I should...
Here in TX I’m not going with anything less than a 10w40 or the 15w50. I ran the rotella way before I had LR’s in my Jeep 4.0L I6’s from day one and I had zero issues. It’s worked fantastic in the LR V8 for me as well.
Not saying it’s the oil to use, but it’s worked with excellent results for me over many years. Sadly it’s going up & up in price lately & I might have to look into other oil’s. I’ve never been a fan of Castrol Oil. They recently had a 15w40 diesel oil that was pulled from the shelves. I’d stick with Mobil1, Valvoline, or Shell/Rotella.
The oil debate is like the large small oil filter debate. Going by the owners manual is great, but a lot has changed in the last 20 years, especially oil, and ways of keeping our LR’s alive. We know way more about the 4.0/4.6L now vs when those manuals were printed and P38/D2’s were rolling off the assembly line.
Using diesel oil? Not so fast
