the best oil

[Skymac]

I only use 10W60 fully synthetic oil for all my motors, that includes motorcycles.
available at any Midas, comes in a gold coloured container.
bit more expensive, but I recon, with the difference.

[Tony Z]

your question is one that you will never get an accurate answer for. So many different opinions, so few facts as to why other than this guy said or he does it this way.
If you search long and hard enough, you might find a running in oil.

My opinion and how I did it a few times.
The cam is the problem issue, new cam and new lifters need to be run in together. Numerous people talk about problems with cam pitting. For this, I use a thin (10W40 or thinner 0W30 depending on what I find) for the initial cam break-in. Then change it out for something thicker.
My 2332 I am running in on semi synth and will go full synth at 1000km. Some people say to use a poor grade oil so things run in quicker - for me, I dont like this idea. If you want to run your rings in with a good oil, find a long steep hill, put the car into a gear where you can maintain your speed, but need to keep your foot on the floor. This builds up temps and runs rings in nicely.

Oil is blood - look how badly you function when yours is full of booze.

BTW, all oil from a decent company (prob not a Midas brand) has sludge dispersant and detergent additives, so dont worry about sludge. But these do get used up, so change your oil regularly and you wont have sludge issues. Even a full synth that does too many miles will build up sludge.


I also have more info to add to this post that I have found, but I need time to do it properly, some very interesting info I found on the Castrol website.

[Tony Z]

I only use 10W60 fully synthetic oil for all my motors, that includes motorcycles.
available at any Midas, comes in a gold coloured container.
bit more expensive, but I recon, with the difference.

Castrol edge????

[Skymac]

Thank you Tony Z
I did not have a picture

[davetapson]

This is hotly debated topic on the 4x4 forums. Dunno if you can compare a 4l V6 with a 40yo AC 1600, but after reading all the stuff thrown out, I finally got convinced by Caltex Delo 400 (Chevron Delo 400 in the long post above).

I was speaking to a guy who does oil assays for companies who use a lot of machinery, as they figure it's best to change the oil when it needs changing rather than some random distance/time period. His comment was that Delo 400 kept it's characteristics for over twice the recommended oil change periods. When I asked him what oil he used in his Isuzu bakkie, he finally admitted Delo 400.

It was useful for me as I owned a petrol hilux and diesel renault - the oil is a multipurpose oil - can use in either vehicle. I figure an oil that can withstand the rigours of a diesel engine has to find a petrol engine a pleasant environment. Sold the bakkie at 140k km and it wasn't burning any oil (not that it should have been, but anyway). The diesel runs much quieter (less clatter) with the Delo. Whether that actually means anything, I dunno, but it makes me happy anyway.

I also fall into the camp that says that just becuase they didn't have multigrades when acvw's were originally designed doesn't mean they may not be a better bet than an old single grade. I'd go with Delo 400 and have done.

However, if I wasn't going to use Delo 400, I'd probably go with Magnatec or the like as they allegedly provide better protection on start up, which is apparently where the majority of the wear happens. May of course be marketing hype.

The consensus on the 4x4 forums is that GTX is better at marketing hype than oil performance, and after using Diesel GTX for a couple of yrs in the Renault I'm disposed to believe them.

All boils down to personal choice - fact is, if you use any modern oil with a reasonable viscosity, you probably can't go wrong.

In the 15 yrs I used bugs as daily drivers (including Namibia / Bots / Zim on and off road) I used SAE 30 or GTX and had long lasting motors. I only ever had to replace one motor, and that was a high mileage 1300 motor in a hard driven baja bug with 215 x 15 rear wheels.

[My bug]

OK, we have four runners. Castrol EDGE and Magnatec, Dello 400 and Shell Rotella, what are the differances in price??? (sorry coming from a students point of view, always consider the $$$$)

Matt

[Tony Z]

Guys

Here is some info I found a while back and have been meaning to put here for ages.

TBN - total base number. Basically the same as pH but with minor differences.

In short, you dont want your oil to be acidic. Oil is generally produced to be slightly alkaline (basic) as with time and carbon ingestion into the oil, it becomes acidic. The number 7 is neutral. Super acidic has a number around 1 while super alkaline is around 14.

Now for some numbers that we have in SA.... all this from the http://www.caltex.co.za website....

Castrol Edge 5W40 TBN = 10.28
Castrol Edge 10W60 TBN = 12.45
Castrol Magnatec 10W40 TBN = 8
Castrol GTX 20W50 TBN = 7.5
Castrol GTX highmilage TBN = 6.9

This in itself says that dino oil (GTX) will start becoming acidic in a very short time, while the semi-synth (Magnatec) will last a little longer and the full synth (edge) will resist becoming acidic for a very long time.

Viscosity....
In short, viscosity is a liquids resistance to flow.
Low number = low resistance = low viscosity.
High number = high resistance = high viscosity.

Viscosity at 40degC
Castrol Edge 5W40 = 83.7
Castrol Edge 10W60 = 160
Castrol Magnatec 10W40 = 100
Castrol GTX 20W50 = 150.3
Castrol GTX highmilage 20W50 = 156.7

Viscosity at 100degC
Castrol Edge 5W40 = 14
Castrol Edge 10W60 = 23.4
Castrol Magnatec 10W40 = 14.7
Castrol GTX 20W50 = 17.12
Castrol GTX highmilage 20W50 = 17.08

I cannot find any automotive monograde products on their website.
Bizarrely this has Edge 10W60 as being thicker at 40degC than the GTX 20W50 range. Which would point towards Edge 10W60 being the oil you dont want to use on a cold morning start. While Edge 5W40 being the best with Magnatec 10W40 not far behind.
This would also point towards Edge 10W60 being the highest load bearing oil out of the list when at operating temps, followed by the dino oils (GTX).

I am slowly getting confused by these figures and must admit that my knowledge on this subject is now running thin. I suppose I need some monograde oils to get a referance spec from.... time for more googling before I write more and confuse myself and you guys further.

[Tony Z]

OK... found a SAE 40 monograde on the American website.

Viscosity at 100degC = 14.1
No mention of viscosity at 40degC

That shows to me that the Caltex multigrade oils seem to match the monograde oils at 100degC.

This to me says that Edge 5W40 or Magnatec 10W40 is definitely the way to go. Thin at low temps, both alkaline and has a 40 weight viscosity at 100degC - pretty much as per VW spec.

I read somewhere (pretty sure it was on this forum) about someone who ran different oils on the highway and measured the oil temps. The 20W50 dino oils were running a few degrees warmer than the 10W40 grades.

this can be explained by the principle by which the stock oil cooler works.... oil pressure.
If the pressure is high, the oil is diverted past the cooler. As pressure drops (oil gets warm), the oil is allowed into the oil cooler. The thicker oils will thus have a slightly higher oil pressure due to their higher viscosity and thus not as much oil will pass through the cooler, creating higher temps.

Now the catch - yes another one.
If a oil is run at too high a temperature, it degrades very quickly and thins out on a permanent basis. I have experienced this with GTX 20W50 where after a high speed stint on the highway the oil is so thin that at idle, you hear all sorts of metallic knocking owing to low oil pressure and low load bearing ability.


Now its your turn to add some comments... maybe you can see some things I have missed. Its getting late now anyway.

One thing that I keep thinking tho..... I think I might have wasted my money buying 5 liters of Edge 10W60 when I should have gone for 5W40. But that said, I had super success with Futron 20W60, so maybe its not a waste.... I'll have to do some more thinking and research.

[hitlers revenge]

Instead of boring us with all this drivel about oil and numbers and W's, just tell us what to use.

Make sure you have the correct answer before January 6 2010.























Thanks for the interesting post Mr. Zee

[davetapson]

My favourite. I see they aim this at truck operators, and seem to aim Havoline at cars... wonder what the difference is.

Oh - and before you tell me it's a diesel oil, it's not - it's a mixed fleet oil, usable in diesel and petrol engines...

I see that it says synthetic. The version sold locally has some form of long chain molecule that gives it properties of a synthetic, but it is indeed dino oil.

I'm not sure of the point of using synthetics if you are going to perform regular oil changes as the main point of synthetics is extended oil change periods (assay tends to show that with delo 400 you can skip every second service as the oil maintains it's properties over that period). The main contender against delo always seemed to be amsoil - here is something interesting off their website:

http://www.c66racing-synthetics.com/Tes ... t11-05.htm

But Amsoil is a synthetic.

[JamesD]

Worth the read and explains a fair amount about oils! there are other oil related articles on the same site...

http://wiki.seloc.org/a/Oil_Labelling_Explained

[Hloni]

Seems to me that the "best oil" is the best marketed oil. Guys, you have done so well by putting thought and research into this, but l still do wonder though despite the facts and figures presented by all, that end of the day, the oil which one uses for whatever application, does not end up being a personal preference.

Just as an example, l was shocked the other day by TOYOTA'S claim of the lifespan of their "specialy engeneered" coolant!

I believe that major companies put a lot of money into research and like wise into marketing. How many of us have tried that "oil free engine oil" which is advertised on VERIMAK, and what were\are the results?

[davetapson]

Seems to me that the "best oil" is the best marketed oil.

Fair comment, esp. as 'a can of the best' is apparently not, according to a number of people, but the marketing is superb.

The easiest way of checking on an oil's 'bestness' is to have a look at its service category - for diesels, it the CI, CH, CG marking, and the higher the second letter, the cleverer the oil. There will be similar for petrol engine based oils, and in theory a CH will always beat a CI etc.

[Tony Z]

and it continues..... it turns out that the viscosity of the winter grade in a multigrade (20W, 10W, 5W, 0W...) isnt measured at 40deg C but rather at -25degC.
See below my email to Caltex and the reply from the UK Technical Manager nogal.....

Good day

I contacted Castrol USA for some information regarding the possibility of one of your Technical data sheets being incorrect and they replied saying the product is European and not sold in USA. I shall copy my original email and paste it below this line (in blue). The full email and reply is below.

Viscosity index in Technical Data sheets - possible error?

I have been looking through the TDS and have noticed a possible error with the Edge 10W60 viscosity index at 40degC. The index says it is 160mm2/s.
Edge 5W40 has a visc at 40degC of 83.7
Magnatec 10W40 has a visc at 40degC of 100
GTX 20W50 has a visc at 40degC of 150.3

why does Edge 10W60 have a viscosity at 40degC of 160, which is higher than
the 10W of Magnatec and also higher than the 20W of GTX? Or is this an error?

Kind regards and seasons greetings

And then the reply

Thank you for your e-mail.



I can confirm that the information given is correct and the misunderstanding may come from the way that the viscosity is evaluated.



Apologies if a lot of the following is familiar to you, but hopefully it will give a clear understanding of where the figures come from.



The viscosity of an oil at 40°C does not directly relate to its stated grade, e.g. 10W-40, it is measured in order to obtain a figure for the viscosity index (VI) of the oil. VI is actually a calculation of the slope of the line drawn between two points on the viscosity chart of the oil and has no units because it is an index. These two points are, traditionally, the viscosity at 40°C and 100°C. The greater the slope of the line, the lower the viscosity index and therefore, generally, the lower the quality of the oil. A line with a steep gradient means that the oil changes viscosity significantly with changes in temperature. A high quality oil will not change viscosity significantly with changes in temperature, and so the line drawn between its viscosity at 40°C and 100°C should be quite level.



If we look at the viscosities at 40°C and 100°C for the oils mentioned we can see that the fully synthetic oils have the highest viscosity indexes confirming that their viscosity changes less than the mineral and part-synthetic oils viscosities do with any change in temperature.

40°C 100°C VI

mm2/s mm2/s

Edge 10W-60 161 23.5 179

Edge 5W-40 83.7 13.75 178

Magnatec 10W-40 100 14.5 149

GTX 20W-50 150.3 18 135



(Please note some of the figures quoted may not tie up with the figures you have seen because I cannot be sure I have looked at exactly the same formulation, but the trend should be consistent)



It is only the viscosity figure at 100°C that is used to define the SAE viscosity grade of the oil. A 60 grade oil (10W-60, 15W-60, 20W-60, etc.) has a viscosity at 100°C of between 21.9 and 26.1mm2/s, a 50 grade between 16.3 and 21.9, a 40 grade between 12.5 and 16.3.



The reason that Edge 10W-60 has the highest viscosity at 40°C is related to the fact that it has the highest viscosity of all the oils at 100°C.



The number in the grade with the W following it is related to the viscosity measured below 0°C for each of the oils and so, even though Edge 10W-60 is thinner than the 20W-50 at cold temperatures and roughly equal to the 10W-40, it is still able to be thicker at 40°C. This is because the synthetic baseoils in the Edge product are able to continue flowing at much lower temperatures than the mineral and part-synthetic baseoils in the Magnatec and GTX products which are adversely affected by waxes and impurities contained within them, causing them to go solid as the temperature drops below -25°C. So even though the Magnatec 10W-40 and Edge 10W-60 products start off ata similar viscosity at -25°C, as the temperature rises the Magnatec product immediately start thinning down compared to Edge 10W-60 until, by the tie the temperature gets to 40°C, Edge 10W-60 is 1.6x thicker. Likewise, although the 20W-50 starts off much thicker at -25°C (in fact the 20W-50 will be almost solid) compared to Edge 10W-60, as the temperature rises the 20W-50 will start to thin down more quickly and, by the time 40°C is reached, the 10W-60 – because its viscosity doesn’t change so much with changes in temperature - will actually have crossed over and will be thicker than the 20W-50. If the 20W-50 had been a 20W-60, we would expect it to have a viscosity at 40°C of approximately 200mm2/s and therefore would start off thicker than the 10W-60 at -25°C and remain thicker all the way up to 100°C where the two oils would be the same viscosity or at least very similar.



Hopefully this has helped your understanding of the viscosity and grades of our oils without wasting your time with information you already understood.



You may find the following link helps confirm the information above:

http://www.rohmax.com/rohmax/en/custome ... sityindex/



Please contact us again should you require anything further.



Regards.

[BigBear]

My oldman swears by

Castrol GTX 20W50

So That is what we used with the last oil change a couple of months back

Can't remember what the guys from VW Trend used last when they serviced it before ...

The old oil looked rather filthy and like a diesel type oil ...

Running on GTX now