[fastscud]

Following on from my other questions:

The owner's manual says 0w30 is only suitable for tempratures between -30C to 10C.

I've seen the GC 0w30 mentioned as suitable for the CRDi.

But given that Australian temperature often go well above 10C, is it actually suitable?

And yes, I'm a little puzzled that 5w30 is suitable up to 40C (according to the owner's manual), but 0w30 is only usable up to 10C ...

[Phil №❶]

I run 5-40 in Oz for extra freeway protection.

[Doggie 1]

I run 5-40 in Oz for extra freeway protection.

Me too.

[rustynutz]

I run 0W40.....

Following on from my other questions:

The owner's manual says 0w30 is only suitable for tempratures between -30C to 10C.

I've seen the GC 0w30 mentioned as suitable for the CRDi.

But given that Australian temperature often go well above 10C, is it actually suitable?

And yes, I'm a little puzzled that 5w30 is suitable up to 40C (according to the owner's manual), but 0w30 is only usable up to 10C ...

I would be so bold as to say whomever wrote the owner's manual oversimplified it.

A 0w30 and a 5w30 (or a 10w30 for that matter) could all be the same hot viscosity, as you wondered. They could all vary by quite a bit too because the viscosity given is not a single viscosity but instead a range.

The GC (German Castrol) 0w30 is in fact almost identical to Mobil 1 0w40 in its hot viscosity. It's just that one is slightly below the crossover between 30 and 40 and the other is slightly above it so determining the different sticker numbers. Probably not by accident either, Mobil might have thought that a wide 0w40 (and theoretically difficult technically) number was easier to market and Castrol might equally have thought that a 30 number covered more vehicles or implied better economy or any number of marketing reasons. All supposition of course.

So, a 0w30 or 5w30 is ok so long as it's not a thin 30! (my qualification). Equally, I think some 40 grades are unnecessarily thick.

[constipated]

So, a 0w30 or 5w30 is ok so long as it's not a thin 30! (my qualification). Equally, I think some 40 grades are unnecessarily thick.

Pip, what's your view of the Australian Castrol Edge titanium 5w-30. Does it fall into your thin or thick 30 grades?

Pip, what's your view of the Australian Castrol Edge titanium 5w-30. Does it fall into your thin or thick 30 grades?

I tried the previous blend just known as Edge 5w30 and my engine "sounded" noisier. There is an account on here but I actually turned off the engine immediately to check I'd really filled it!

I took it out soon after. The new one with titanium I have neither tried nor have looked at too hard. The 0w40 Edge looks for all the world like the German Castrol although it's truly impossible to know. It's on my short list and Rusty uses it, as he said.

To answer the question though, the original 5w30 was thin by my ears and thick by the specification! It actually falls at the high end of the range, something like 12.2 Cst or thereabouts without checking.

FWIW, opinion only.

[bryanj86]

Hmmmm Not sure... I think that is SLIGHTLY too thin?  I know they use 5W-40 in my car at Hyundai.... personally I'd wish they'd use thicker oil, particularly in summer but they insist on maximum economy hence the thin oil?

Hmmmm Not sure... I think that is SLIGHTLY too thin?  I know they use 5W-40 in my car at Hyundai.... personally I'd wish they'd use thicker oil, particularly in summer but they insist on maximum economy hence the thin oil?

Without knowing exactly what they use I'd say 5w40 is not thin at all; thick to start and thick to finish. Whether a thick oil offers good protection when at running temperature does not really need any debate but the other side is whether it offers less when cold, and that is important because unless you are a taxi driver you need at least one cold start each outing.

And it's worthwhile considering if the following is true: Oil thicker than necessary to stop the metal bits touching is just wasting fuel pushing it around.