Oil question in a V.6es9j

[Stickyfinger]

I note that Citroen say a *w40 in the Xantia v.6 but a *w30 in a C5 v.6 ....TOTAL seem to agree

Wondering why ?

Due to the *w30 type oils being NA when they launched the Xantia v.6 ?

[CitroJim]

I always used 10W/40 in all of mine without any issues at all Alasdair... Diesel fleet oil at that!

It could be an age-related thing.. Perhaps in 1997 when the ES9 debuted the 10W/30 oils of the day were not quite up to the mark...

I don't really know, just a surmise...

[xantia_v6]

I think that it is probably to reduce the official CO2 figures by a tiny margin. I would stick with the thicker oil.

[GiveMeABreak]

According to the Citroen recommended oils in the guide I put together, the engines have both types and as the C5 Mk I, II and III all have ES* engines in their 3 Lt models, the guide shows both types depending on your engine badge number,

Guide here on the Wiki:
https://www.frenchcarforum.co.uk/wiki/C ... arbox_Oils

The guide dosn't distinguish between models - only engine type and badge.

And note the statement (same for C5 2013> models incidentally):
"For example the use of grade 10W40 is limited to the temperate countries (from - 17 °C to + 37 °C) or to a hot climate". For any other application, the grade must be chosen in line with the climatic zone of the country of use. (refer to guide).

[Harlequin]

But fully synth , semi synth or Castrol gtx mineral?

[GiveMeABreak]

Mineral oils are a lot thinner and contain more impurities - requiring more frequent oil changes. Semi synthetic oils cost less than fully synthetic oils and are a combination of both synthetic and mineral oils, and provide increased protection over a wider engine temperature range. If your car is designed to use semi-synthetic oil, then you should use semi synthetic as a minimum, but a fully synthetic oil will provide the best protection and performance for newer engines and probably older ones too.

[CitroJim]

I would stick with the thicker oil.

I fully concur

[lexi]

Need to remember that a C5 v6 is a totally different engine with hundreds of changes from the old one. There is a doc somewhere listing the engineering of it.
I would say 10-40 semi synth is around the mark for an older V6.

[Stickyfinger]

Only the VVT Cylinder head is different really, how much difference that makes I am not really sure.

[lexi]

No, many many other changes on materials, weight and design from block to pistons etc etc. It's in the doc.
VVT do need thinner oil generally as well.

[Harlequin]

ES9J4 > ES9J4S > ES9A

that says to me the J4S was very similar to the J4

[GiveMeABreak]

Some interesting info here, seems Porsche retuned the PSA version of the engine and introduced VVT ready for the 607 and C5....
http://www.wow.com/wiki/V6_ESL_engine