Oils ain't oils :)

[digifish]

This is an interesting exchange between myself and Holden 'Customer Service' doesn't exactly fill me with confidence...you see the oil rating 15w-40 for example is a (W)inter, cold - 40 (100C) viscosity measure.

AND

My local holden dealer suggested I use Shell Helix Ultra...

So customer emails Holden to check -

From: digifish

I have an Astra CDTi and note the manual has recommendation of 10W-30 or 15W-40 oil (A3, B4). I am interested in using a 100% synthetic, 'Shell Helix Ultra' from my first 3000km inspection service, this has a rating of 5W-40 (A3, B4). Will this be OK to use?

digifish

-----Original Message-----
From: Holden CAC

Dear digifish,


Thank you for your email.
We advise that Holden cannot recommend using a different viscosity oil than that specified in your owner's handbook, as we have not tested our vehicles like this and cannot advise what effect this will have on your vehicle.

Yours sincerely,
Holden Customer Assistance Centre

-----Original Message-----
From: digifish

Thank you for your response.

Can I ask if this is a standard response based on the viscosity mismatch or has this issue been considered by an engineer?

The Shell Helix Ultra 5W-40 differs from the 15W-40 and 10W-40 recommendations in terms of the cold viscosity rating. i.e. 5W is measured at - 25°C, 10W is measured at -20°C and 15W is measured at -15°C. From this you will see that the SAE 5W-40.

The hot viscosity rating 40 meets your recommendation and a 5W is in fact a superior number to the 10W.

-----Original Message-----
Dear digifish,

Thank you for your reply.
Holden's oil viscosity recommendation refers to the rating of the oil printed on the bottle, and has no relevance to hot or cold rating.
Should you choose to use an alternative oil rating based on the information you supplied in your most recent email, you do this at your own consequence.

Yours sincerely,
Holden Customer Assistance Centre

-----Original Message-----
Dear digifish,

Thank you for your reply.

Please follow the recommendations as per your owner's manual. We do not recommend you use the oil you enquired about for your vehicle.

We hope this clarifies Holden's final recommendation on the matter, and we advise that we will not enter into any further correspondence with relation to alternative oil viscosities.

Yours sincerely,
Holden Customer Assistance Centre
---------------end-------------

Now the last email is fine...just the responses inbetween have me very concerned about the quality of Holden Customer service.

digifish

PS: Holden eventually changed their mind and decided 5W-40 was ok - Scan from 07 Manual (thanks Alix)...

http://www.digifishmusic.com/public/images/CDTiOil SpecUpdate.jpg

[Lt Ketch]

Holden's oil viscosity recommendation refers to the rating of the oil printed on the bottle, and has no relevance to hot or cold rating.

Science aside, as im certainly no chemist or engineer, this bit concerns me the most!

[cybermonkey]

for your information, an SAE grade of 5W will cause the oil to thin less at 100c. the only oil you should be using in your engine is 15W-40 or if you live in the hotter parts of oz, 15W-50. I dont understand why you are making such a big fuss. if GM specify that this engine needs 15W-40 to provide maximum lubrication, then that is what you should use. Using the wrong rating will just increase friction in the engine and reduce its life.

[digifish]

for your information, an SAE grade of 5W will cause the oil to thin less at 100c. the only oil you should be using in your engine is 15W-40 or if you live in the hotter parts of oz, 15W-50. I dont understand why you are making such a big fuss. if GM specify that this engine needs 15W-40 to provide maximum lubrication, then that is what you should use. Using the wrong rating will just increase friction in the engine and reduce its life.

You are wrong. The 5W is the cold pour point. This has nothing to do with the viscosity at 100C, the fact it is 5W-40, 40 means that the viscosity at 100C will be in the specified viscosity range. The same as any other 40 oil (0-40, 15-40 20-40).

The fuss was that they don't seem to know what the numbers on the bottle mean.

digifish

[Blue_Dvl]

that is quite a poor response form manufactuer, I personally prefer fully synthetic also. I would probably consult your local Holden Dealer Service Manager for clarification as your more likely to speak with someone with a mechanical background.

I cant see the problem, but with warmer weather on its way you may want to consider the slightly thicker viscosity..... somethng around a Mobil 10w40 or similar.

[digifish]

that is quite a poor response form manufactuer, I personally prefer fully synthetic also. I would probably consult your local Holden Dealer Service Manager for clarification as your more likely to speak with someone with a mechanical background.

I cant see the problem, but with warmer weather on its way you may want to consider the slightly thicker viscosity..... somethng around a Mobil 10w40 or similar.

Thanks

The suggestion for Shell Helix Ultra 5W-40 was the dealers...(service manager), I was interested in checking with Holden :)

BTW 5w-40 is the same viscocity (at 100 deg C) as 10w-40.

The CDTi manual states that it wants 10W-30 or 15W-40 A3, B4 oils.

digifish

[EL BURITO]

sorry mate, if u have ever rang then up as well u get the same responce, refer to the owners manuel, te ppl in the call center are just that pass o info they read off the screen. Dont ask Holden ask the Mechanic face to face so he can explain and surrgest wat to do next.

[NUTTTR]

Honestly, they don't print the manuals just because they want to print stuff. 15w-40 WILL have a different viscosity @ cold start temps and warming up than 5w-40. I would highly unrecommend (if that's a statement that can be used) using 5w-40. Although it's not exactly cold here, your car will use significantly more oil with 5w than 15w. It might not blow enough to see, but it'll drink it, and technically, you are voiding your warranty on the engine. Mineral oils and synthetic oils are about the same these days, i mean, obviously, if you are sitting in traffic all day @ 40deg and flogging the crap out of the car 24x7, then it'll make a difference. For normal driving mineral oil would want to be (you dont' HAVE to, but it'd be a good idea) changed more often. That's about it. Just used 15w-40, dont' buy cheap ****, don't buy top of the range. I've always hated shell oil's, as they used to leave a 'varnish' effect whereever they leaked/dripped. Maybe it's changed nowadays, but hey...

Aaron

[digifish]

Honestly, they don't print the manuals just because they want to print stuff. 15w-40 WILL have a different viscosity @ cold start temps and warming up than 5w-40.

The viscosity/temparature curve has little to do with the W rating at temparatures above 0 deg C.

As most of the engine wear happens in the start-up period then getting the oil to circulate quickly is paramount (you want thin oil). You also want it to be not too thin at temparature.

BTW: If an engine uses oil, that's not damaging or a problem so long as you keep the levels up to scratch.

I agree with you dino-oil replaced regularly is better than Synthetic changed infrequently. However the issue I am facing is that I need...
SAE W15-40 A3 B4 certified oil. Shell Helix Ultra is the closest I have found...but it's SAE 5W-40 A3 B4. 5W-40 by definition must meet the 15W-40 standard. The exact viscocity vs temparature curve is impossible to tell from the SAE rating, this simply specifies a point at which oil pours and a viscocity at 100 degrees C.

And to prove that with modern oil chemistry that intuition does not work, I know Shell Helix Ultra is thinner at 15C than 100C.

digifish

[mr_sikma]

what do you mean by A3 and B4???

i was under the impression that the first number is the thickness of the oil at cold temps and heats up to the next number.

so 0-40 would end up being the same thickness at 15-40 when hot!

[low astra]

Viscosity is ordinarily expressed in terms of the time required for a standard quantity of the fluid at a certain temperature to flow through a standard orifice. The higher the value, the more viscous the fluid. Since viscosity varies inversely with temperature, its value is meaningless unless accompanied by the temperature at which it is determined. With petroleum oils, viscosity is now commonly reported in centistokes (cSt), measured at either 40°C or 100 °C (ASTM Method D445 - Kinematic Viscosity).

Multi-weight oils (such as 10W-30) are a new invention made possible by adding polymers to oil. The polymers allow the oil to have different weights at different temperatures. The first number indicates the viscosity of the oil at a cold temperature, while the second number indicates the viscosity at operating temperature.

At cold temperatures, the polymers are coiled up and allow the oil to flow as their low numbers indicate. As the oil warms up, the polymers begin to unwind into long chains that prevent the oil from thinning as much as it normally would. The result is that at 100 degrees C, the oil has thinned only as much as the higher viscosity number indicates. Another way of looking at multi-vis oils is to think of a 20W-50 as a 20 weight oil that will not thin more than a 50 weight would when hot


hope that helps

[digifish]

what do you mean by A3 and B4???

i was under the impression that the first number is the thickness of the oil at cold temps and heats up to the next number.

so 0-40 would end up being the same thickness at 15-40 when hot!

The 'Grade' numbers - first number is called the (W)inter number 5W for example and the second is at the 100 degrees Celsius.

They measure two different things, the W number means that the oil meets a specific viscosity at various low temperatures. 5W is tested at -25C, 10W at -20C, 15W at -15C, and 20W at -10C. But that does not mean a 5W multi-grade oil is necessarily going to be thinner than a 15W multigrade at 20 C.

The higher number is a specific viscosity rating at 100 deg Celsius

The A3/B4 are extra standards -

A3 High performance and / or extended drain
B4 For direct injection passenger car diesel engines

digifish

[digifish]

Prologue...

It turns out that you can't buy an oil that meets the spec 15W-40 ACEA A3, B4 in Australia.

My dealer after talking to Holden had them respond after 2 days that 5W-40 was acceptable

...apparently they are re-printing the manuals. What a bunch of dweebs at Holden :(

digifish

[mr_sikma]

so you cant get a full synthetic in 15w-40 ??? is that what you are saying?

but holdens now are saying you can run 5w-40 if u want to run fully synthectic?

do they use mineral 5-40 in oil changes etc??? even on new cars?

[MatsHolden]

On the Barina they state you can use 15W-40 or 15W-50.

[digifish]

1. so you cant get a full synthetic in 15w-40 ??? is that what you are saying?

2. but holdens now are saying you can run 5w-40 if u want to run fully synthectic?

3. do they use mineral 5-40 in oil changes etc??? even on new cars?

1. Not that is ACEA A3 B4 compliant.

2. Yes

3. Dunno. I don't think you can get a mineral oil that is 5-40

digifish

[digifish]

On the Barina they state you can use 15W-40 or 15W-50.

Yes the 15W-40 grade was not the issue, ACEA A3 B4 is...the Astra CDTi needs A3 B4.

digifish

[mr_sikma]

i have read up on the oils and stuff now, but still a bit confused!

holdens say to run a 15W-40 or 15W-50

whats the difference between the 2?

also whats the difference between a 15W-40, 5W-40 and 10W-40 etc?

with the second number, the higher the number the thicker it is?

and i know the first number is measured at low temps and the second number is at high temps, but the lower number the thinner?

thanks

[digifish]

holdens say to run a 15W-40 or 15W-50

whats the difference between the 2?

also whats the difference between a 15W-40, 5W-40 and 10W-40 etc?

with the second number, the higher the number the thicker it is?

and i know the first number is measured at low temps and the second number is at high temps, but the lower number the thinner?

thanks

The 15W-40 is thinner at 100C than the 15W-50 while they are both the same viscosity at low temp.

So yes, the higher the second number the thicker it is (at 100C) or thinner if it's lower.

digifish

[mr_sikma]

but doesnt oil thin out when hot?

so why is the 2nd number such a high number compared to the first? if the higher number = the thicker oil?

thanks ;)

[digifish]

but doesnt oil thin out when hot?

so why is the 2nd number such a high number compared to the first? if the higher number = the thicker oil?

thanks ;)

It comes back to multi-grades vs single grades...

?W-40 means that this oil is the same thickness as a 40 weight oil at 100C
?W-50 means that this oil is the same thickness as a 50 weight oil at 100C

A 50 weight oil is thicker than a 40 weight oil.

OK

what does the lower W part mean. It's related to the cold pour point, that is the point at which frozen oil starts to flow when a container of it is tipped 90 degrees to gravity.

I think from memory this test is carried out at 0F (-18 C). Similar reasoning applies, when cold, a 5 weight oil is thinner than a 10 weight oil, so these numbers relate back to viscosities of single-grade oil weight at -18 C.

A single grade oil is just that an oil with no viscosity modifiers.

digifish

[digifish]

To concude this saga...Holden eventually agreed with me :p

http://www.digifishmusic.com/public/images/CDTiOil SpecUpdate.jpg

Thanks to Alix for scanning the 07 CDTi Manual.

[sooty]

So i should fill mine up with 5w-40 lol :D?

[digifish]

So i should fill mine up with 5w-40 lol :D?

The manual says it's OK :p

[sooty]

And guess what...both mobil and shell online say we should use 10w-40...just to add something else into the equation :D

[digifish]

And guess what...both mobil and shell online say we should use 10w-40...just to add something else into the equation :D

They just haven't updated their info. There was no recommendation for the CDTi for about 10 months after it was launched ;)

[MAD-16V]

Talking to the penrite rep the other day at work about this very topic.

Using a 10W/40 as an example - The first number is the start up viscosity.
The second number is the protection factor.

Oil cannot get thicker with heat - this is a misconception - Instead it thins with heat.
The second number relates to the stabilizers added to the oil and hence the protection factor.

When looking to buy oil for your vehicle - Try to stick to the manufacturers spec for the start up weight ( You would only ever use a 5W or a 0W in very cold climates ).
Then you want the protection factor to be as high as possible - The next time you look at oils, have a look at the varying protection factors between all of the brands.

So using a semi synthetic oil such as the Penrite HPR10 - This gives you a start up weight of 10W - And a protection factor of 50.
Now compare this to a Fully synthetic such as the Sin10 - Wich gives you a start up weight of 10W and a protection factor of 70.

We sell almost every kind of oil at work - Castrol - Nulon - Gulf Western - Motul - Shell - Penzoil - Penrite - Mobil etc etc - So I am able to do comparisons on a very large scale.

Personally I went from a nulon "Fully Synthetic 10W/40" to a Penrite semi synthetic HPR10 and the difference is huge - The fuel economy has increased and the car runs much quieter.

Hope this helps.

[digifish]

Talking to the penrite rep the other day at work about this very topic.

Using a 10W/40 as an example - The first number is the start up viscosity.
The second number is the protection factor.



If the rep told you that it's a bit misleading.

The higher number is just a viscocity rating at 100C.

taking a step back time, lets consider -

5W - 40

The winter number (5W) is the pour point. The temparature at which the oil will start to flow (5 is not the temp btw, I think a 0W oil pours at around -50 degrees deg C, 5W is about -40 deg C). As you can see that is way over-specified for Aus conditions.

The 40 is the viscosity rating relative to a straight 40 weight oil at the same temparature. A 50 oil will be more viscous than a 40 oil at 100C.

And this is the point of my post. It may be that the manufacturer didn't design the engine for that weight. You will be increasing shear forces on the oil, increasing fuel consumption through increased back pressure/drag etc. More is not necessarily better for the second number.

BTW: I am not sure if it has happened yet but you could in theory make an oil that gets thicker with temparature, you just need polymerisation to occur or polymers to uncoil sufficiently. Ever made gravy? :)

IMO its best to stick with the narrowest range of viscoities for your climate as it means the oil is relying less on viscocity modifiers to maintain the range of viscocities.

digifish

[cbrmale]

The 'W' on 5W is 'weight' not 'winter'. That is, we have 5 weight base stock with polymers added. A previous post described the process of the polymers unravelling as the oil temperature increases.

The manual for my MY7.5 says 0W-30 / 40 or 5W-30 / 40. I am currently running 0W-40 synthetic which gives me a marginally thinner oil on start-up (Canberra having many sub-zero mornings) plus the protection of 40 weight equivalent when hot. In any case, this oil is in the manual.

One caution: the more complex the polymers the more they degrade over time. That is, a 5W-40 will degrade quicker than a 15W-40: so that the oil may not thicken at normal temperature. We used to have this problem with motorcycles which pull high revs all the time, the polymers used to shear and the oils used to break down to the base weight. The cure is to change the oil more frequently, in my case I change every six months. I do this anyway to flush out water condensation and all the other things that float around and are too fine to be filtered.

[digifish]

The 'W' on 5W is 'weight' not 'winter'. That is, we have 5 weight base stock with polymers added. A previous post described the process of the polymers unravelling as the oil temperature increases.
...
One caution: the more complex the polymers the more they degrade over time. That is, a 5W-40 will degrade quicker than a 15W-40:

Two points...the W does not mean weight.

http://www.valvoline.com/carcare/articleviewer.asp?pg=ccr20040601ov&section=hm

The A3 rating is extended drain so the point about the oil not maintaining viscosity is a bit moot. If it meets the spec it meets the spec.

digifish

[cbrmale]

I've just done a little research on oils (Mobil1 5W30 is what Opel use by the way). Petrol engine standard A3 (extended drain) is met by many average quality mineral oils such as the Castrol Magnatech I put in my wife's Barina, and even old GTX-2. This being the case, there is no reason why Opel needed to modify the viscosity ratings of their petrol engines, as there are many compliant mineral oils in the 15W40 range on the market.

The diesel cars needs synthetic to meet standard B4, but this standard does not apply petrol engines. And yet in January, petrol engines were changed to 0W-30/40 or 5W-30/40. Also in January, new petrol engines were introduced (the redesigned 1.8 and the new 2.2). Maybe the new engines rather than the spec is the reason for the change.

[Alix]

Also in January, new petrol engines were introduced (the redesigned 1.8 and the new 2.2). Maybe the new engines rather than the spec is the reason for the change.

But the diesel didn't, and has the same recommendations in the manual.

The petrol engine updates came in the MY7.5 didn't they? - I've got the MY07 CDTi, and those same oil recommendations are in my manual (for the diesel), as per the scan posted above.

EDIT: Thanks for tracking down the Mobil 1 use from factory. Doesn't matter now (I topped up with Castrol Edge 0W-40), but others might be interested. Where'd you find that?

[cbrmale]

I found the Opel reference on the Mobil1 website.

The oil spec change came with the MY7.5 update, and my car is one of the first MY7.5 shipped. I'm quite happy, a lighter weight is good for cold starts and warm-up, especially here in Canberra (we get below zero quite a bit, and as low as minus seven). I park my car in a garage so my start temperature is about five, but it is cold once you get onto the street. And now I don't have any warranty problems running 0W-40, it's in the manual.