Like many, I have searched for a better oil than the JLR recommended C1 5W30 “dumb ass” (as Christian & Vera at LR Time would say) given that this “C1” specification is now dropped by ACEA.
Of course, in older pre-DPF vehicles, you can find some mid-SAPS C2/C3 5W40 (smart ass) oil, but there is no C1 5W40 oil in existence for Euro 6 compatible vehicles with DPF. Or is there?

I have been looking for months, and finally I found a supplier of a high-grade 5W40 low-SAPS C4 oil (</=0.5 Sulphated Ash content) and compatible in all other parameters (other than viscosity of course) save Phosporous, which is only very marginally more (0.09% vs 0.05%). Of course, there is no UK distributor, so I have contacted them for volume pricing. I cannot find this grade of oil from any other UK supplier, please correct me if I’m wrong?

Would this be something that others are interested in, given that the only reason for choosing the ultra-low viscosity (5W30) is to achieve better fuel consumption figures at the expense of engine wear? As the owner of a TDV6 model, and wanting to keep the vehicle, I would like to look after the engine as much as possible. (Slightly OT, I just read yesterday that sometime in 2016 Ford Dagenham switched to a forged crankshaft, and this can be confirmed on the vehicle by a 16mm crank pulley bolt, vs a 14mm one on the older, presumably weaker crankshafts. Does this information bear scrutiny?)

Hopefully, this will be an interesting debate!  “If it ain’t broke, don’t fix it” -where’s the fun in that?

Yes, I agree. I have been searching this afternoon but went down a rabbit hole of C2/3/4 specifications and lost interest, temporarily.

Watch this space. They are sending a quotation, so I can check the price is OK.
To get anything like a decent price it will be minimum £20K worth!
This is direct from the Emirates, no middle-men.
Not getting too excited as yet, because if the price is too high, no-one will bite….. “If it ain’t broke, don’t fix it” -where’s the fun in that?

/Devils Advocate

So, for an engine you’re worried about oil feed to the crankshaft, you’re wanting to add a thicker oil, with more phosphorus to clog the DPF ?

- - - - - - - -

Not sure what I think about it. I’ve not really read anything that easily explains why C1 is gone. Maybe I should just buy a massive drum of C1 ! And carry on regardless ! V8 or else ...

(Double-post deleted) “If it ain’t broke, don’t fix it” -where’s the fun in that?

Last edited by Gremlin500 on 28th Mar 2024 10:17pm. Edited 1 time in total

@Fisha:

Yes! For the reasons explained. 0.04% difference. C4 is sold as being suitable for DPF’s. It’s classed as “Low SAPS” its mainly the Sulphur Ash which clogs the DPF’s, and that is exactly the same in C1 & C4. C1 5W30 OTOH, is more prone to diesel dilution due to its already very low (some say too low) viscosity. Remember when all our engines had 20W-50 oil, in the days when fuel was cheap, and car makers weren’t chasing every last nanopercentage of mpg?  “If it ain’t broke, don’t fix it” -where’s the fun in that?

Last edited by Gremlin500 on 29th Mar 2024 1:05am. Edited 1 time in total

Of course its not JLR approved though, so those with a warranty would loose it overnight if you used the wrong spec oil.
Devils advocate!  2018 SE SDV8 4.4 Byron Blue

🥱

@Kot: I always assume folks on here are above average intelligence, and aware of warranties etc. Especially your good self

It is JLR themselves who have used the “wrong spec oil” IMHO they don’t give a sh*t as soon as (typically) month 36 expires.

Too many Devils and not enough Advocates? 😈

Don’t folks agree with Christian & Vera, and wish for a solution for their L405’s? “If it ain’t broke, don’t fix it” -where’s the fun in that?

I am waiting for Sam's Motor and Machine report on his L322, although he has had his DPF and EGR effectively deleted.

It becomes one of those rabbit hole things once you start reading !


There's no doubt, with C1 grade gone, there needs to be an accepted alternative to move towards, and C4 fits the nearest bill in terms of specs.

In the typical UK climate Is there really going to be *that* much of a difference to the kinetic viscous flow of a 5W40 versus normal 5W30 at normal operating temps in an engine ? From what I read, not that much.

My current thoughts are that is more important to look at the HTHS of an oil. C4 has a higher minimum HTHS rating, which will improve protection on the high load parts ( the tdv8 and its relatively low revs for a given power output raising the question about wanting as good a high load protection as you can get), so would that not go some way to what you are looking to achieve by going towards the 5W40 ?

This thread sums it up well I think:

https://bobistheoilguy.com/forums/threads/...40.296084/

So at the moment, in the absence of 5w40 C4 being common place, the best you can easily achieve is 5W30 C4, and that in reality, the C4's higher HTHS will be of benefit to the engine anyways ???

I think going forward, I'm now of the mind for 5W30 C4 at this stage. Regarding oil dilution, I'm changing the oil every 5 to 6k miles at the moment, which again I think is possibly as good as you can reasonably do. V8 or else ...

Gremlin500 wrote:

Don’t folks agree with Christian & Vera, and wish for a solution for their L405’s?

Gremlin500 wrote:

🥱

@Kot: I always assume folks on here are above average intelligence, and aware of warranties etc. Especially your good self

It is JLR themselves who have used the “wrong spec oil” IMHO they don’t give a sh*t as soon as (typically) month 36 expires.

Too many Devils and not enough Advocates? 😈

Don’t folks agree with Christian & Vera, and wish for a solution for their L405’s?

Sometimes you need to explain the obvious, many of us still have extended warranty beyond the 36 months and you cant ignore the "elephant in the room"

As we are told Sulphated ash is what blocks the DPF and C4 equals C1 here, so would tick the box.

@fisha good points regarding HTHS being better C1 >2.9 and C4 3.5 so a higher oil film strength as well.

But Ford and JLR have set the standard after years of testing etc, and we are often reminded by the guys selling us the oil to Always use the right SAE viscosity grade, ACEA specification and most importantly the correct manufacturer specification – and choose a high-quality oil with a balanced additive pack.

If JLR changed the spec tomorrow we would all change in a heart beat, until then we all have a choice of which rabbit hole or to follow  2018 SE SDV8 4.4 Byron Blue

Ah, that’s better! Some nice healthy debate going on!

Why should we assume Ford & JLR are correct, and have our best interests at heart? Engines fail despite servicing “by the book”, buildings collapse, and pandemics decimate the population, because most of us blindly follow “ those in the know”. We need to question everything in life: maybe they just might be right, but what if not?

Basic ICE engineering has not changed much in the last few decades, but the pressures on the manufacturers to produce ever “cleaner” engines have, so it’s not all driven by engine component protection and longevity anymore, it’s driven by the need for manufacturers to conform to the latest regulations, irrespective of longevity, they don’t care, and the few who take up expensive extended warranties are an insignificant cost versus the majority who don’t bother and can be circumspectly dismissed in month 37 or whenever the initial warranty term runs out.

5W40 “thicker” oil is hardly in the same league as EP90, rather a very mild increase in viscosity to help offset the deleterious effects of diesel dilution ravaging our engines on a daily basis. Has anyone run a viscosity check on an oil sample of 5W30 after an official 16000 miles? I bet it’s more like 0W20, great for a Siberian Winter, but not so great at keeping the shiny bits apart under load in the UK.
Again, I ask the question: what has significantly happened since the 70’s normality of Castrol GTX 20W50 in terms of the running clearances, engine speeds, bearing shell diameters/widths, and oil pump pressures, to warrant deliberately putting such blatantly thin oil in our engines, and then knowingly allowing it to get rapidly further diluted?  “If it ain’t broke, don’t fix it” -where’s the fun in that?

@Fisha:

You raise some very good points, thanks for joining the debate.
I know all this might be splitting hairs to some extent, of course.
But, concerning the environment, everyone should be doing their bit, and right now, I‘m changing my oil every 2500 miles or 6 months. If I could make that every 5000m and 12 months without risking my engine longevity, that would be good for me, and good for the planet. But, because we don’t trust the manufacturers, and their official 16000m service intervals are laughable, we feel the need to change our oil more frequently, and their own service indicators agree with us.
Of course, there will be those who don’t bother, and move the vehicle on to become someone else’s problem.

If I can get a supply of the 5W40 C4 at a reasonable price, it’ll be going in my engine, for sure.
In my view, it’s a no brainer.
I’m soon to test my current 5W30 C1 oil after 2500m next month after service, to check residual viscosity, diesel dilution, and metallic particulates. “If it ain’t broke, don’t fix it” -where’s the fun in that?

Quote:

Again, I ask the question: what has significantly happened since the 70’s normality of Castrol GTX 20W50 in terms of the running clearances, engine speeds, bearing shell diameters/widths, and oil pump pressures, to warrant deliberately putting such blatantly thin oil in our engines, and then knowingly allowing it to get rapidly further diluted?