Castrol 0W30 vs 0W40

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Can someone explain the difference between these two oils? I know the viscosity differences, but not sure about the API ratings. 0W30 is SL, and 0W40 is SN. Is the SN oil not lower on additives?
 
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SN is the newest API service category. It supersedes SM, just as SM supersedes SL. The additive levels are different.

Whether or not it's "better" is up for debate. Generally speaking, the requirements get stricter with each new version. You can compare them here:
http://www.lubrizol.com/EngineOilAdditives/ACEA/RelativePerformanceTool/default.html

My two cents is that the 0w40 is the better oil for most applications. It's a newer formula that largely matches or beats the older 0w30. Many people here will disagree with me.
 
SN is not lower on additives. A energy conserving SN may have lower ZDDP levels vs a energy conserving SL rated oil. But a 40 grade oil is not held to this standard.

Also ZDDP is not everything to consider.
 
Originally Posted By: Bluestream
0W30 is SL, and 0W40 is SN. Is the SN oil not lower on additives?

No. In fact their add packs are pretty much identical. The only difference is that the 0w-40 has slightly higher 100C viscosity. I still don't understand why Castrol 0w-30 continues to be produced and sold now that Castrol 0w-40 is widely available.

0w-30 VOA:
http://www.bobistheoilguy.com/forums/ubb...0_S#Post2365765

0w-40 VOA:
http://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3008930/Castrol_Edge_0w40_VOA#Post3008930
 
Thanks Guys, I am getting low on my stash of GC 0-W30 and I can buy the 0W40 cheaper in a 5 liter jug. I Thought the SL rated oils have more zinc, which is good for high RPM motors, I use this oil in my 1.8L VW, and my Sea-Doo and Ski-Doo 4 strokes...
 
Originally Posted By: Bluestream
Thanks Guys, I am getting low on my stash of GC 0-W30 and I can buy the 0W40 cheaper in a 5 liter jug. I Thought the SL rated oils have more zinc, which is good for high RPM motors, I use this oil in my 1.8L VW, and my Sea-Doo and Ski-Doo 4 strokes...



Zinc is not necessarily better for high RPM motors. The benefits of ZDDP are greatly exaggerated, especially for modern engines. There are newer additives that offer the same or better performance.

Unless you are running some old-school flat tappet engine, I see no need for elevated ZDDP.
 
There was near hysteria on BITOG when there promised to be a reduction of some additives moving from SL to SM. Now, I can't see a need to even run an SL lube in any of my vehicles.
 
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Originally Posted By: Quattro Pete
I still don't understand why Castrol 0w-30 continues to be produced and sold now that Castrol 0w-40 is widely available.

It's no different than there being 5w-30 in QSUD, PP, and PU. They're just as redundant; I guess it's just preferences.

As for those wondering about the API specification, as QP, dparm, and others have stated many times over the past many, many months, the API specifications of these two oils are almost completely irrelevant. The current number of North American and Japanese vehicles that call for a non-ILSAC 0w-30 or an SM/SN 0w-40 can be counted on one hand.

I'm sure GC and the Castrol 0w-40 could virtually abandon the API specifications altogether and the sales would barely take a dent.
 
Originally Posted By: Bluestream
Can someone explain the difference between these two oils? I know the viscosity differences, but not sure about the API ratings. 0W30 is SL, and 0W40 is SN. Is the SN oil not lower on additives?

Like Garak said, API specification means nothing. It is not as strict as ACEA, and especially as let's say MB 229.5.
My opinion: both are equally good. Both are sold in Germany as Full Synthetic, which means they have mostly GrIV and V in pack.
I personally used 0W30 for a long time, tried M1 0W40, and if my experiment with this M1 ESP fails (meaning oil does not retain TBN in good numbers) I am going back to 0W30.
 
Originally Posted By: Quattro Pete
Originally Posted By: Bluestream
0W30 is SL, and 0W40 is SN. Is the SN oil not lower on additives?

No. In fact their add packs are pretty much identical. The only difference is that the 0w-40 has slightly higher 100C viscosity. I still don't understand why Castrol 0w-30 continues to be produced and sold now that Castrol 0w-40 is widely available.

0w-30 VOA:
http://www.bobistheoilguy.com/forums/ubb...0_S#Post2365765

0w-40 VOA:
http://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3008930/Castrol_Edge_0w40_VOA#Post3008930


Do you think it would be okay to mix the two for an oil change? For example, 4 quarts 0W-30 and 3 quarts 0W-40?
 
Originally Posted By: kjbock

Do you think it would be okay to mix the two for an oil change? For example, 4 quarts 0W-30 and 3 quarts 0W-40?



Yes, you can do that. A requirement for API certification is that the oil must safely mix with any other API oil. Some members like to do that with a 0w20 and 0w40 because that manufacturer doesn't offer a 0w30 (for example).

I'm not really sure why you would want to mix them, though. They're virtually identical. Just buy the [newer formula] 0w40 and be done with it.
 
Originally Posted By: dparm
I'm not really sure why you would want to mix them, though. They're virtually identical. Just buy the [newer formula] 0w40 and be done with it.

+1
 
Originally Posted By: dparm
Originally Posted By: kjbock

Do you think it would be okay to mix the two for an oil change? For example, 4 quarts 0W-30 and 3 quarts 0W-40?



Yes, you can do that. A requirement for API certification is that the oil must safely mix with any other API oil. Some members like to do that with a 0w20 and 0w40 because that manufacturer doesn't offer a 0w30 (for example).

I'm not really sure why you would want to mix them, though. They're virtually identical. Just buy the [newer formula] 0w40 and be done with it.


I already have some 0W-30 in my stash. I want to switch to the 0W-40 and may need to mix the two to use my stash up. Thanks for the info, though.
 
Originally Posted By: kjbock
I already have some 0W-30 in my stash. I want to switch to the 0W-40 and may need to mix the two to use my stash up. Thanks for the info, though.

Still don't see the point of mixing. Just use your 0w-30 first, and after you're done, switch to 0w-40.
 
I'm going to use 0W-40 for my next DIY change in my BMW.

That choice being driven primarily due to its slightly higher viscosity and newer formulation.

I thought the introduction of Castrol 0W-40 meant the end of GC.

Locally, it has meant the availability of GC dropping from three (3) auto parts stores to only one (1).

I hope GC continues to be available in the US.

I may move my son's RX8 to GC if I can buy it in an Advance Auto oil change deal for 32 bucks.
 
The API SL 0w-30 version that is listed on Germany's and France's websites show that the formula now contains titanium, and the flash points are now 210C and PP = -60C like the 0w-40 version of Edge Professional A3 (FP = 211C). This means that the 0w-40 that we get in the US is not just a thicker version of the 0w-30 -

Germany - Castrol EDGE Professional A3 0W-30

France - Castrol EDGE Professional A3 0W-30
 
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I guess we need to do a VOA on the latest batches of Edge 0w-30 and 0w-40 here in the US to see if anything's changed recently on this side of the pond. The 0w-30 VOA we have is a few years old.
 
From Google translate -

Castrol EDGE Professional A3 0W-30
Boosted with TITANIUM FST ™ - Strength for Maximum Performance
Description
Castrol EDGE Professional with TITANIUM FST ™ is our best and most powerful passenger car engine oils
an excellent
Provide engine performance even with critical engine load.
The development of smaller more powerful engines and by the need for more efficient vehicles
lower
Emissions driven. Only the engine oil separates highly stressed engine components
from each other, so it must be strong and stay strong.
Castrol EDGE is our strongest product line.
The TITANIUM FST ™ doubles the lubricant film thickness, prevents tearing of the lubricating film, reducing the
Friction.
Castrol EDGE Professional products with TITANIUM FST ™ C02 are the world's first motor oils, neutral
are produced.
Micro Filtered and with his typical fluorescent color is the Castrol Edge Professional product range with
TITANIUM ™ FST your guarantee of professional quality.
Application
Castrol EDGE Professional A3 0W-30 is suitable for use in gasoline and diesel automobile engines,
for a motor oil ACEA A3/B4 type, API SL / CF or earlier specification of the manufacturer recommends.
Castrol EDGE Professional A3 0W-30 has been approved by leading car manufacturers. Please
stick to the details of the chapter on the technical specifications and to the User
Of your vehicle.
Benefits
Castrol EDGE Professional A3 0W-30 FST with TITANIUM ™:
• exceeds the highest standards of premium producer
• offers excellent flow properties around the sensitive engine components within easy reach (cold start)
• also offers long service intervals Performance
• provides maximum performance even under extreme load
• Reduces engine deposits and wear

Typical Physical Characteristics
Unit test methods
Castrol EDGE Professional A3 0W-30
Density @ 15C, Relative
ASTM D4052
g / ml
0.8416
Viscosity, Kinematic 100C
ASTM D445
mm ² / s
12.2
Viscosity, CCS-35C (0W)
ASTM D5293
mPa.s (cps)
5880
Viscosity, Kinematic 40C
ASTM D445
mm ² / s
73
Viscosity index
ASTM D2270
None
164
Pour Point
ASTM D97
° C
-60
Flash Point, PMCC
ASTM D93
° C
210
Sulfatsche
ASTM D874
% Wt
1:13
Specifications
ACEA A3/B3, A3/B4
API SL / CF
BMW Longlife 01
MB-Approval 229.3 / 229.5
VW 502 00/505 00
 
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