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I own a Ford Mondeo Ghia-X, Auto. here in the UK and the car is fitted with the 2.5 Litre, 24 valve, V6, Duratec engine and has travelled approximately 22 thousand miles, using Castrol 5W30 GTX Magnatec.(A semi synthetic oil.) Since the Ford warranty is coming to the end of its term, I am going to carry out my own oil and filter changes which, on previous vehicles, I have always carried out at 6000 mile or 6 month intervals.
I have access to a supply of fully synthetic motor oil, at a competitive price, and I seek your advice on its suitability for this engine.
The oil is marketed by Vauxhall/Opel(GM) and is the latest oil for use with their extended service interval schedule. Its full name and specification, as marked on the can, is as follows:- GM 5W30 Long Life Super Synthetic Engine Oil.
Specification: GM-LL-A-025: GM-LL-B-025: ACEA/A3/B3/B4: API SL/CF.
With the 5W30 rating and associated high specification, I assumed it would be suitable for my engine, so contacted Ford before committing myself. They responded by saying that only 5W30 oil conforming to Ford Specification WSS-M2C913-B can be used for service fill, but that 5W30 oil to ACEA A1/B1 can be used for top up.
Not knowing who manufactures the GM oil, I contacted Shell UK asking if their Shell Helix Ultra, which is a similar spec to the GM oil and conforms to ACEA A3/B3/B4, was suitable for my engine. They replied that only their Helix F 5W30 was recommended for my car, as it met the relevant Ford specification, as quoted earlier, and aslo met ACEA A1/B1-98, (The latest ACEA spec is dated 04, which makes it 6 years out of date!) I also asked what were the negative aspects of using a 5W30 ACEA A3/B3/B4 oil in place of an A1 and they said fuel economy would be sacrificed and that it may be incompatible with bearings, valve train and piston components, and that the oil could age prematurely, shortening the oil change interval considerably. Castrol, in response to a separate query, stated that A3 was not superior to A1, but was just different.
After lots of research on line I do not beleive this. The major difference I can see between ACEA A1/B1 and A3 specifications is that the High Temperature High Shear (HTHS) figures for A1 must be between 2.9 and 3.5 mPa.s (cP) wheras A3 must exceed this figure. This would, I assume, adversely affect economy, but not by much.
What do all you experts out there think of this situation? Should I stick with a semi synthetic castrol or Shell oil, conforming to the Ford spec, or should I use what, in my opinion, is a superior product, that is fully synthetic and which I can get at half the price. Sorry this my first posting is a bit long, but I wanted to give the full picture.
Regards
Kayball
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I highly recommend you visit www.bobistheoilguy.com

This issue has been beat to hell. Here in the US, 5w-20 is quickly becomming the grade of choice. Search the site on the issue.

ACEA A3 you must meet a HT/HS of 3.5 or greater whil A1/B1 are long drain specs with HT/HS of less then 3.5. Both are tough specs and signify a quality oil. My Honda calls for a 5w-20, however, many run ACEA 30wt oils. I could go on all day....check out the site.
No reason given, just a mixed blurb, with most of it extracted from the introduction to the ACEA spec sheet which describes A1/B1 oil as not being suitable for some engines. They have used almost the same wording to say why A3 oil should not be used when B1 is recommended! The ACEA full spec is printed at:- http://www.acea.be/ASB/Download.nsf/Category0Files/F5167E6B75D68AF5C1256F4600263CD9/$File/ACEA2004%20oil%20sequences-DEF.pdf
Disappointed with the response to my original query.
To summarize; what are the disadvantages, or dangers, of using an ACEA A3/A4/B4 oil in an engine that specifies an A1/B1 oil?
All the applicable discussions I can find on the 'Bob is the oil guy' site refer to using A1/B1 oil in an engine designed for A3 oils.
Please guys, help me decide if using the GM-LL-A-025 approved oil in a Ford that specifies A1/B1 is worth the cost saving.
quote:
Originally posted by Kayball:
...what are the disadvantages, or dangers, of using an ACEA A3/A4/B4 oil in an engine that specifies an A1/B1 oil?
From what I can tell, the A3 is a more robust oil requiring a higher HTHS than the A1. So long as you use the correct viscosity, I don't see where you can go wrong. In fact, I would think the A3 would be better to run than the A1.
quote:
Originally posted by Kayball:
... what are the disadvantages, or dangers, of using an ACEA A3/A4/B4 oil in an engine that specifies an A1/B1 oil?
All the applicable discussions I can find on the 'Bob is the oil guy' site refer to using A1/B1 oil in an engine designed for A3 oils.
Please guys, help me decide if using the GM-LL-A-025 approved oil in a Ford that specifies A1/B1 is worth the cost saving.


Hi Kayball,

I'm not sure where your "cost saving" comes from? Will you be extending your drain intervals beyond 6 mos/6k mi? If so, then I feel you're completely justified in switching from an A1/B1 oil to an A3/B3/B4 oil. These better ACEA classes really give you an edge in oil durability & additive robustness. When you combine them in a European full syn, extended drains become a non-issue because the oil provides superior engine protection for much longer intervals.

With this full syn available to you, there are a couple of things to keep in mind:
1) You're in Europe, where the label "Fully Synthetic" means a superior PAO/Group IV based oil. Here in the U.S. that's not the case, & less durable Group III based oil can carry the "Fully Synthetic" label.
2) GM-LL-A/B-025 has no HT/HS rating attached to it that's comparable to the ACEA scale. From everything I've been able to gather, it's strictly an environmentally-based spec aimed at earning GM monetary "credits" for fuel efficiency & fluid conservation (extended drain intervals). In fact, when the spec was first released, oils meeting all three ACEA classes (lowest=A1/B1; better=A5/B5; best=A3/B3) were approved for it.
3) Forget about the API rating. The ACEA specs are so far beyond what we have here in the US that it's meaningless except to meet what's called out in American owner's manuals.

As far as cautionary tales are concerned, I can tell you that when I switched my '90 Saab 900 (2.0L 16v I4) from the A1/B1 Castrol 10W-30 Syntec (not a "true" syn oil here) to the A3/B3 Mobil 1 15W-50, I saw absolutely no change in MPG. And if anything, the improved HT/HS rating actually means the oil will last longer, not shorter. I had the oil tested after 6,500 mi & 13+ mos, & it looked nearly new for trace wear metals. The analysis is over on BITOG.

Your first line of defense in protecting your engine is the oil film!! The more durable the film, the better your protection. Your second line is the additive package, but now you're looking at much thinner protection, so you want to avoid going into that territory as much as possible. Beyond that, you're into metal-on-metal & it gets ugly fast.

HTH. Smile
Hi Eiron.
Sorry I haven't been back to the forum reently but my topic seemed to have died until you came along. Thanks alot for the input, which goes with how I have been thinking. The cost saving I make is because I can buy the GM oil at trade price which is only UKP12 for 5 litres.(I have access to the GM trade club - don't ask!) For an oil of this spec it is a gift. The normal retail is in excess of UKP24. From all correspondence on the list, and other sources, I conclude that the only reason Ford state that an A1/B1 oil must be used is to coroborate their MPG figures which were achieved with this grade. Thanks again to all for their response. This realy is a great site.
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