Engine Oil
 

Is it necessary to use 0W-30 oil ??

The list of recommended oils in the owners manual looks like 5W-30 might be ok for the UK/IRL climate as long as it meets A5/B5 specification, any thoughts would be much appreciated.

In a word, NO!
The Acea A5/B5 spec is important, but the 0W part is only required for starting below around minus 25C, which is 10C below the temp that Tesco diesel will gell at and block the fuel filter.

If you want a more accurate minimum safe cold start figure when using BP or Shell winter diesel (Gells at minus 21C), look up the pour point figure in the TDS and add 10C. The result for Castor oil Edge will be around minus 33C.

A major brand (Castrol, Mobil, Shell or Liqui Moly) full synthetic 5/30 (Or 5/40 for an older engine that is burning oil) is fine in winter and odd enough a 10/30 is perfectly OK in summer.

There are three main reasons why 0/30 is recommended, firstly manufacturers like, "One size fits all figure" and they don't want law suits from some muppet that calls a dealer in the South of Spain to complain that his battery failed after his holiday to Siberia in the winter.
Secondly there is a very slight improvement in MPG figures between an 0W and a 10W oil.

Thirdly it looks cool in the advertising, as Castrol keep hyping 0W30 or 40 oils! It's a well proven fact that unless you are in Siberia for the winter Gulag holiday season (No heated garage or plug in power points), it makes no real difference in engine wear terms, as all normal engine oils are too thick for simple oil film protection when an engine is first started. Modern oils rely much more on the anti wear, extreme pressure and friction modifying additives (Zinc, Boron and Moly compounds mostly) than the viscosity improvers that allow the 30 or 40 grade to act as an 0W when cold. As long as it can be pumped around the block all is well.

I would note that when selecting oil grades it is worth figuring out where the actual kinematic viscosity is at 100C, as SAE grades are a range and there are differences between one 0/30 and another. That can be important in noise terms with some older diesels.
Castrol Edge 0/30 is at the top end of the 30 range and nearly the same when warm as Mobil 1 0/40 in viscosity terms, as M1 is at the lower end of the 40 range.

I'm a mid range sort of chap, so use Shell Helix Ultra 5/40, mostly cos it's the cheapest major brand full synthetic from a good Germebay dealer near the Polish border. I do spice it up with half a can of Liqui Moly Ceratec, but even that combination is almost 20 Euros cheaper than LM Synthoil High Tech 5/40, the true liquid Gold in German oil engineering terms.

PS: The tought of not using an OEM filter from a real Volvo dealer or Skandix has never crossed my mind. They are worth every cent in both performance and quality terms. If the can ain't white, it's not right!

5W/30 it is so!!

Thanks for the very informative reply skyship007.

I changed my fuel and oil filter in January this year. Changed the oil at the same time. It now has Castrol Edge 5W/40 in it and loves it.

If you use Castrol, their oil finder works well:

http://ew5.earlweb.com/search.php?si...=6&model=volvo

Some newer cars do list Edge 0W30 and although this is a real good winter oil, it's best to move up a grade for a higher mileage diesel to an 0 or 5/40.

I would recommend steering well clear of the DPF rated (Acea C3) Edge Turbo Diesel 5/40, as the normal Edge (A3/B4) 5/40 is much better for a DPF free engine.
I tested that C3 oil and my old diesel did not like it, with some real bad UOA figures from Blackstone.

UMM, This seems to be the current lists of Edges!!

Castrol EDGE 5W-30

Castrol EDGE Longlife II 0W-30

Castrol EDGE Professional A5 0W-30

Castrol EDGE Professional BMW LL04 0W-30

Castrol EDGE Professional C3 0W-30

Castrol EDGE Professional E 0W-20

Castrol EDGE Professional H 0W-20

Castrol EDGE Professional H 5W-30

Castrol EDGE Professional H C2 0W-30

Castrol EDGE Professional LongLife III 5W-30

Castrol EDGE Professional OE 5W-30

Castrol EDGE Professional V 0W-20

Castrol EDGE Sport 0W-40

Castrol EDGE Sport 10W-60

Castrol EDGE Turbo Diesel 0W-30

Castrol EDGE Turbo Diesel 5W-40

Castrol EDGE 5W-30

Castrol EDGE Longlife II 0W-30

Castrol EDGE Professional A5 0W-30

Castrol EDGE Professional A5 5W-30

Castrol EDGE Professional BMW LL04 0W-30

Castrol EDGE Professional C3 0W-30

Castrol EDGE Professional E 0W-20

Castrol EDGE Professional H 0W-20

Castrol EDGE Professional H 5W-30

Castrol EDGE Professional H C2 0W-30

Castrol EDGE Professional LongLife III 5W-30

Castrol EDGE Professional OE 5W-30

Castrol EDGE Professional V 0W-20

Castrol EDGE Sport 0W-40

Castrol EDGE Sport 10W-60

Castrol EDGE Turbo Diesel 5W-40 is what I used ...

I use the 0 30 purely because that is what is recommended. After reading sky ships reply how would I know what other oils are suitable for the dpf in simple terms is this what the a5 b5 specification means Ie low ash Ect?

Firstly I would just stick to the recommended oil or a good major brand equivalent with the same Acea specs until the oil consumption rises from a post break in period and that might be a long time.

The A specs are for petrol engines only, the B specs are for diesels without a DPF, BUT just to complicate things there are now two DPF sets of specs. The C ones and the E ones. Your owners handbook should list which C or E one is required, but this PDF has the definitions:
http://www.acea.be/uploads/publicati..._Sequences.pdf

In fuel economy terms I would be inclined to stick with Edge 0/30 and try LM Ceratec, as the actual viscosity of Edge 0/30 is fairly high. Ceratec is perfectly OK for DPF diesels and produces some real good results. In fact I was just looking at this example:

http://farm4.staticflickr.com/3793/1...e113b069_b.jpg


The Moly and Boron figures are higher as they are the main active compounds. The all important Iron figure tracks the oil change interval, so it should be much higher (70 to 80), as should the other wear metals (3K to 8K mile OCI) like Aluminium and Lead. They might be tending to trend down in break in terms, but that takes a long time.

Now I'm very confused!!