Engine Oil

Technical Area Routine Servicing
2

A bit of advice please guys to a maintenance novice.

I have done an oil change and used Mobil 3000 FE 5w30 which is a fully synthetic oil. Before I purchased this I checked the spec in the owners handbook for my Mk3 and it met the spec for API SL as recommended.

At Halfords I had the choice of Halfords own brand 5w 30 Ford semi synthetic or the Mobil and I selected the Mobil.
A friend of mine who is into cars has suggested that I would have been better off using the semi synthetic as I might get blow past and lose oil as the synthetic is too thin.

Have I made a mistake and should I change the oil again or will it be ok to stick with what I have. Am I worrying unnecessarily?

3

5-30 mobil oil I have it in my mk3 1.8 no problems paid £24 at halfords

4

  The oil you have used is fine for your car, you do not need to worry at all!  Go to the MX5parts website and you will see they supply the same oil for your car.  

Regards  Geoff Peace.

 

 

5

Don’t understand why anyone would think a 5W-30 synthetic would be thinner than a 5w-30 semi-synthetic. They will generally have the same temperature and cranking characteristics, the difference will be in the formulation of the base oil.

ANY oil meeting the API-SL spec and the correct viscosity, which I assume to be 5W-30 in this case would be fine. Chances are that over time the synthetic will stay in grade for longer which is only really of consequence if you plan to extend the drain interval beyond the usual 12 months.

Any difference in wear rates in cams etc will be down to the ad pack used but even then if all the oils meet the same API/ACEA spec they will perform perfectly adequately.

6

 

Hi Mick,

I looked into this quite carefully and your friend is right to say the Mobil 3000 is relatively thin compared with some other 5W30 oils.

The 5W part is a cold cranking specification but the SAE30 can vary. That said the thinnest 30 cannot be thinner than the thickest 20 if that makes sense.

Mobil 3000 is a top oil and meets the latest Ford 913C spec. This was uprated from their previous 913B spec to such an extent that, although the spec doesn’t specifically say it must be synthetic, in practice it needs to be to meet it.

Included in this spec is that it is a Fuel Efficient oil which is why it is chosen from the thinner end of the SAE30 viscosity spec.

Now, what your friend doesn’t appreciate is that this engine is designed for this thin oil. Indeed in the US (I was there earlier this year and had a good look around Wallmart) the most common grade (and the one specced for our cars in the US handbook) is actually 5W20!

So no problem at all, you chose the right oil and it is the exact one recommended by Mobil. I have 2 x 5L waiting in the garage for the next services on our Mazdas and have used it for many oil changes so far.

here’s the recommendation from Mobil UK for the 1.8

http://ew5.earlweb.com/recommendations.php?modelyear=&vehicle=5376&site=105&region=120&language=5&brand=106

and here for the 2L,

http://ew5.earlweb.com/recommendations.php?modelyear=&vehicle=5377&site=105&region=120&language=5&brand=106

 

 

7

Thanks for the advice guys, I shall sleep soundly tonight!!!

much appreciated

Mike

8

I have used this in my 2ltr Sport  http://www.mobil.co.uk/UK-English-LCW/carengineoils_products_mobil-1-esp-formula-5w30.aspx#

Have I put the wrong 5w 30 oil in?

9

I think MX-5 Parts actually sell the XE version but the FE version is Ford spec, and 4 cylinder Fords have Mazda MZR engines (aka Ford Duratec), so it’s the right one.

To be fair, Mobil Super 3000 is on the margins of “fully synthetic” as it is a cheaper hydrocracked dino oil, not in the same league as Mobil 1, which is a proper PAO synthetic, effectively built from the ground up from smaller molecules.

What is amazing about the MX-5 is that it doesn’t normally use a drop of oil between services, even when running-in. The engine is made to very fine tolerances. In comparison, VW Group engines (petrol or diesel) use a fair bit of oil, although it’s not a major cost.

10

Hi MickAP,

ESP is fine according to my owners handbook we can use any of these in the UK as they all fall in the range -20C to +40C

 

Here’s a chart of SL and above spec oils I put together a while back from manufacturer’s data sheets in descending order of thickness using the cSt 100C figure. It shows how the “fuel efficient” oils and Mazda’s own are blended to the lower end of the viscosity band,

 

 

11

Rogerzilla

Very few of the Mobil 1 oils are type 4 or 5 oils. Mobil announced some years ago they were in a lot of cases going over to type 3 hydrocracked oils as the availability of POA’s was getting tight. They make the base stock for the type 3 in the UK.

On the comment another poster made with regard to thinness of the oil.

If you look at oils they tend either these days to be an A5/B5 or A3/B4 in the better grades. The A3/B4 had better sheer and anti wear characteristics up to a few years ago over A1/B1 so by default tended to be towards the thicker end of the spectrum as these oils tended to be for 15k to 18k drain intervals.

The A1/B1 of a few years ago were thinner for better fuel economy but less wear and sheer resistant. Now all the big names have reformulated to the 2010 spec ACEA and are uping their A1/B1 to A5/B5 which gives the added protection for long drain intervals but also reduces the viscosity to reduce puming loses therefore better fuel consumption. Magnatec 5W/30 for Ford or the mid priced Mobil 3000 FE.

Most of these Ford spec oils are A5/B5 with Type 3 base stocks. The Mobil ESP is not a hydrocraked oil but is made for the latest emmission controlled vehicles and also long drain. So a more premium product but way above what is required by an MX5 which today is a very kind engine to it’s oils and does not need the extra aditives and lower ash.

On the other hand the ESP is not that more expensive than the type 3 mixes say £15 a tub in most cases.

12

Google this to find the Exon Mobil pdf that gives the details of Group 3 Mobil 1 brews

mobil-1-new-live.pdf

13

My understanding is that Mobil 1 “New Life” 0W40 (the original Mobil 1) is still a PAO oil. As a very general rule, anything with a cold viscosity of SAE 5 or more is unlikely to be PAO (it’s really hard to get the SAE 0 rating without it).

I may change to 0W40 when the car is out of warranty. I know engines and oils vary, but the difference in cam wear on a VW VR6 engine is shocking when you compare one run on 5W30 to one run on 5W40 or 0W40 - the thinner oil just doesn’t have the film strength, it seems. The fuel economy penalty is probably about 1mpg.

14

I really wouldn’t worry about it and certainly wouldn’t compare our engines to a VW Roger. They have some strange things, we had a PD (pump deuse) engine in a Passat sport a few years ago that would only survive on their special oil (made by Castrol I think) and even then they’re constantly changing the specs. Our Mazda/Ford engine is very forgiving and long lived as indicated by the very loose spec for oil in the handbook. I have a friend with a previously unloved 1.8 version done 130K and sweet as a nut, just don’t let the level fall too low :slight_smile:

15

Rogerzilla

You appear to disagree with Exxon Mobil the makers of Mobil1 about the base oils they use.

I am no expert but I suggest you read the following,  then come back on this one.

Exon Mobil produced the presentation I linked to in I’m informed around 2007 and advised that for 0W/40 New Life they were going over to the VISOM group III+ base stock that was not a POA base oil but that they would add POA additives. Page 28 to 30 refer.

The also said that they would not advise users except in Germany again page 30 refers.

They further advised they would change the base stock to the GTL group III+ base stock in 2010.

I quote from the Exon Mobil presentation

“Visom is the only non-PAO stock that can deliver the required performance to formulate a 0W grade oil that meets European OEM engine oil specifications. Visom is not available to our competition.”

In Germany an oil that is not POA based cannot be called a synthetic oil. It has to be called a HC hydrocracked oil if it is a Group III or the later Group III+.

Go here to the Mobil1 UK site and it sates all the oils are fully synthetic. That term has never been legally challenged in a UK or US court. 0W/40 New  Age an excellent non low Ash oil good for cars designed  from say 1980 to mid  2005 roughly is called fully synthetic.

http://www.mobil1.co.uk/synthetic-engine-oils.aspx

 

Now go to the Mobil1 German site and it advises all the Mobil1 oils are SHC Synthetic Technology. So they are referring to them as hydrocracked.

http://www.mobil1.de/produkte/new-life-0w-40.aspx

 

Further if you use a translator they advise.

Both motor oils are made from crude oil that is pumped from the ground. The difference is that synthetic oils are prepared in a modern refining process and characterized pure and of higher quality than conventional oils. The unique molecular structure allows increased impurities in the refining of the oil to be removed. The oil is pure and can be tailored according to the requirements of modern engines and provide more power reserves.

 

So if you still want to believe that Mobil1 0W/40 which we both agree is a great oil is still made on a POA base then that is fine but I would say it is misguided.

Have a great weekend