Engine Oil - Cause of confusion?

Technical Area Routine Servicing
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Hopefully this thread won’t turn into a “pros and cons of a particular brand of oil” thread, but will be a repository for any other sources of disinfomation!

I always follow the handbook when choosing oil, so went into my local motor factor this morning for oil of the correct grade i.e. A3 OR A5 5W30. Picked it off the shelf where it resided next to the 5W30 A1 oil and went to the counter.

So the man says “Are you putting it into a Vauxhall?” (On the packaging it says recommended for Vauxhall and Opel). Nope, says I, but its the correct grade. “What car is it?” - so I told him, and he came back with “its the wrong stuff, the Mazda uses a Ford engine, this is what you should have” - and takes me to the 5W30 A1 oil, which has a Ford recommendation on the front. After a bit of discussion I said I’d just pop out and double check my workshop manual, just to make sure. To be honest he was so sure, having looked at his computer, that I almost believed him. I’d already looked at this web site a few weeks back, out of curiosity http://www.driverstechnology.co.uk/oils.htm, so felt I understood enough to be able to make the right choice

So I rechecked the handbook (of course) but also looked at a can of 5W30 A3 oil I already had - same packaging, ame VX/Opel recommendation on the front, and a list on the back of it’s compatbilty with specific VW and BMW grades. And Renault, and a couple of others.

Back to shop, picked up the 5W30 A3 pack, took it to counter. Same recommendation, so I showed him the info from my handbook and also the back of the package, and surmised that just because Vauxhall recommend this oil, it doesn’t mean its only suitable for Vauxhalls!. So I bought the oil (the right one!), and got the lecture etc. and also the “What you put in your car is of course your choice, but we have to pass on the recommendations on our database”

So I checked the Castrol web site for my car (2007 1.8) and it says - Magnatec A1 (The Ford recommended one on the shelf)! Not what my handbook says.  Oops I’ve mentioned the Brand I use, silly meEmbarassed

What’s the point of this diatribe? - Well, how many people on this forum are confused about oil, why are they confused - and how many cars are going around with the wrong oil in them (not just MX5’s). Is it due to advice of the sort I had this morning?

How many people have their cars services by the little man around the corner who bases his choice on such information?

Scary, really.

If I get a VW/Clone diesel (as I may) I think I’ll check the web sites for thier recommendations, against a copy of the handbook for the car if I can get one, BEFORE I buy! Then if there’s a discrepancy …

So, anyone else had similar experiences - and what did you do?

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If your hand book recommends 5-30 oil then keep to that.  Look at a different specification on the pack, it should say SL or SM, any lower, say SJ no!    Another guide is to go to the website of Comma oils and input your car details. It will recommend the correct oil for your car, then download the technical data sheet on the oil and all will be revealed.

Regards  Geoff Peace

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The specs are controlled by an organisation called ACEA but they only put the spec and test sequence together, the oil blenders are on their best behavior to produce to the spec there is no ACEA police to check they produce to the spec unlike the GM Dextros spec and the various VW specs.

A1/B1 is a spec that is based on max fuel economy and was what Ford used as they did not do over 12k miles oil change intervals. It is at the thin end of the 5W/30 range with added anti friction additives.

A3/B4 is what Vauxhall /Opel/GM recommend. It is a a blend that does not shear as quickly as the A1/B1 that is it stays thicker longer and therefore is used in long oil change intervals that are say 15k miles but that tends to be for cars that do long journeys not lots and lots of short journeys. It is at the thicker end of the 5w/30 range and would give slightly less fuel economy. It has more anti shear additives and less low friction additives than a A1/B1 blend.

Castrol Magnatec do both and you can see the viscosity difference on the spec sheet

The B4 bit is the extra stuff for use in a direct injection diesels that tend to have a little bit extra fuel pass the piston rings.
If you read the specs A1 is allowed more wear metal than A3 after a test run but things have moved on in the past 2 years.

Both Castrol Magnatec for Fords and Mobil Super 3000 for Ford are a A1/A5 spec. The A5 spec has the fuel economy of the A1 blend with the better shear and less metal wear and long drain interval of the A3 spec.

Therefore if you run a Mk3 and change the oil at 12k or below the A1/A5 will give the best fuel economy as it is a lighter oil. Neither Ford or Mazda do longer oil change intervals.

If you run a Vauxhall or VW then you would go towards an A3/B4 due to the longer oil change intervals and their general engine characteristics.

eddie






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Geoff

The API specs SM,SF etc are not really based on UK and Japaneses cars but on US cars. The ACEA specs are designed around smaller higher tech engines.

The latest API Spec some years ago SL then SM then SN major on reducing piston deposits.

Have a look at this tool.

http://origin-qps.onstreammedia.com/origin/lubrizol/Markets/EngineOilAdditives/100132RPtool2012Deploy/rp/pc/index.html

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No problem Richard :). The handbook says 5W30 API SL (or later) and that’s what you bought. Both Castrol and Mobil sites recommend the Ford 913C oil which is also (surprise surprise) a 5W30 SL but is a slightly lighter oil from the lower end of the SAE 30 viscosity scale sometimes referred to as Fuel Efficient (FE). Mazda oil is this lighter oil made by Total but your choice is fine.

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What a minefield.

Has to be said, I’ve never paid attention to the “A” rating of the oil, just found a decent semi synthetic 5/30 (usually on a deal at Opie or Euro Car Parts) and put it in. That said, I always change my oil 2k miles early in my road cars, sooner for the ones I take on track. I’ve never experienced an issue.

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There’s a lot of nonsense talked about oil.

It is a minefield because today you have so many different viscosities, blends, Mineral, Semi and Synthetics of which there are differences within as well, and that’s not to mention all the different makes.

If you use on-line oil selectors such as from Opie, Castrol or Halfords you will find they all recomend different oils anyway, some even different viscosities.

Take MX5 parts they recomend 10w/40 in Mk2s but then recomend 0w/40 as an upgrade. For a Mk3 5w/30 or 0w/40.

Also there seem to be different recomendations for the same car dependant on country

Your handbook will also give a choice of viscosities on that graphic they include.

It is truly confusing.

My advice is not to get too tied up with oil choice, as long as it’s a good quality and changed regulary it really won’t hurt your engine if say you use a 5w/40 or 0w/40 instead of a 5w/30 or 10w/40. What it might hurt is your wallet paying for an uneccesary expensive oil.

I use Opie Oils, their selector and advice from Oilman is always very good.

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[quote=Phil S]
There’s a lot of nonsense talked about oil. It is a minefield because today you have so many different viscosities, blends, Mineral, Semi and Synthetics of which there are differences within as well, and that’s not to mention all the different makes. If you use on-line oil selectors such as from Opie, Castrol or Halfords you will find they all recomend different oils anyway, some even different viscosities. Take MX5 parts they recomend 10w/40 in Mk2s but then recomend 0w/40 as an upgrade. For a Mk3 5w/30 or 0w/40. Also there seem to be different recomendations for the same car dependant on country Your handbook will also give a choice of viscosities on that graphic they include. It is truly confusing. My advice is not to get too tied up with oil choice, as long as it’s a good quality and changed regulary it really won’t hurt your engine if say you use a 5w/40 or 0w/40 instead of a 5w/30 or 10w/40. What it might hurt is your wallet paying for an uneccesary expensive oil. I use Opie Oils, their selector and advice from Oilman is always very good.

An excellent common sense down to earth post if I may say so Phil S.  

Regards  Geoff Peace.