: 0w or 5w?



jwall09
07-20-09, 09:47 AM
Amsoil has its recommendations:
Engine Oil
Grade 1......API*[1]
SAE 0W-30 Synthetic Signature Series Oil
SAE 5W-30 Synthetic Motor Oil
SAE 5W-30 XL Synthetic Motor Oil

I live in Kansas City, Missouri where the temp isnt as crazy as Texas and other southern states. Should i go for a 0w for the best oil or would that potentially be to thin?

WillySTS
07-20-09, 10:11 AM
0w-30 is best for all climates.

Florian
07-20-09, 10:23 AM
my oil fill cap says 5W, so thats what I use.


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CIWS
07-20-09, 10:26 AM
my oil fill cap says 5W, so thats what I use.


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:yeah:

inurok
07-20-09, 10:27 AM
my oil fill cap says 5W, so thats what I use.


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I was about to type the same thing.

WillySTS
07-20-09, 10:36 AM
my oil fill cap says 5W, so thats what I use.


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Mine says that too, but in the Amsoil lineup, the 0w-30 is better oil and only comes in 0w-30, the 5w-30 is lower quality oil. If I didn't use Amsoil, I would probably use 5w-30 simply because it says so.

C66 Racing
07-20-09, 12:04 PM
Mine says that too, but in the Amsoil lineup, the 0w-30 is better oil and only comes in 0w-30, the 5w-30 is lower quality oil. If I didn't use Amsoil, I would probably use 5w-30 simply because it says so.

I agree - the AMSOIL Signature Series oil is their best oil and the one I'm using in my 06 CTS-V. But, both the Sig Series 0w30 and the SAE 5w30 use a Group IV PAO basestock and are very similar. If you are uncomfortable with the 0w30, go with the SAE 5w30 which is a very close alternative. The XL 5w30 uses a Group III highly hydroprocessed mineral oil basestock similar to that used by most other synthetics on the market today.

Using the AMSOIL 0w30, my car has been seeing wear numbers below the labs univeral averages:
Cadillac CTS-V Used Oil Analysis (http://www.c66racing-synthetics.com/TestResults/CTS-V%20AMSOIL%20UOA.htm)

Also keep in mind that a 0w isn't necessarily "thinner" than a 5w.

A fluid’s viscosity goes down as it heats up. The first number in a multi-grade oil’s rating is its viscosity grade when “cold”, the second its viscosity grade when “hot” (100C). Despite the 2nd number being higher, the oils viscosity is about 5-6 times lower at 100C than it is at 40C.

To make a 5W-30 oil, one starts with a 5W oil and adds viscosity improvers. These VIs have the property that in cold temperatures their polymers coil up, contributing little to the base oils viscosity measurements. At higher temperatures they uncoil to reduce the base oils loss of viscosity as it heats up. So when the VIs break down (shear down) one is left with properties of the original base oil (the 5W stuff). Thus over time, a low quality 5w30 could over time shear down to a 5w20, or worse. Good synthetics do not need as much VI as conventional oil so in general don’t shear down as fast. Since a 5w30 will need less VI than a 0w30, again in general it will perform better since there is fewer VI to shear down and there is proportionately more basestock in the 5w30 since it isn’t being displaced by VI. That said, there are other higher costs additives and basestocks that can offset this effect. I feel that this is shown in the oil's High Temp High Shear rating. For example, the AMSOIL Sig Series HTHS is 3.2 vs 3.09 for the Mobil 1 5w30.

As can be seen from the above test info, the viscosity of the AMSOIL 0w30 is almost exactly the same as that of the Mobil 1 at 212F, which is the nominal oil temp, so even though it is a 0w vice a 5w, it really isn't "thinner".
:cheers:

Florian
07-20-09, 01:21 PM
Mine says that too, but in the Amsoil lineup, the 0w-30 is better oil and only comes in 0w-30, the 5w-30 is lower quality oil. If I didn't use Amsoil, I would probably use 5w-30 simply because it says so.

I dont believe Amsoil is the cats meow....I put in the oil that was put in there from the factory. That way, if it ever takes a shit, I have no issues.


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CIWS
07-20-09, 02:24 PM
If an average owner uses a good quality oil, and changes it on a regular basis before it should be at the end of a service life they are doing their engine no harm. The Problem with some folks comes in because they want to buy the cheaper stuff and/or wait until they have to change it. Already many "experts" say that the cycles of every 3000 miles for normal oil and 5000 miles for synthetic is really too soon and it has plenty of service life left beyond those marks. But if a synthetic user is having it changed roughly every 5000 miles ( I personally go to 8K in this car) then any good quality oil will serve them and their car's engine well.

Florian
07-20-09, 03:36 PM
I change every 7.5K miles....seems to be the right interval.


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hcvone
07-20-09, 05:46 PM
Amsoil SAE 0W-30 Synthetic Signature Series Oil is as good as it gets, run it in my BMW and Benz and all my American cars/trucks. :)

inurok
07-20-09, 05:51 PM
Amsoil SAE 0W-30 Synthetic Signature Series Oil is as good as it gets, run it in my BMW and Benz and all my American cars/trucks. :)


Spoken like a **Authorized Amsoil Dealer** :lildevil:

WillySTS
07-20-09, 07:21 PM
Spoken like a **Authorized Amsoil Dealer** :lildevil:

Right...Us Amsoil Dealers got to stick together. I'm an Amsoil Dealer too but not an Authorized Vender on this board.

I chose to use Amsoil for the same reason that I bought and STS-V, so we know it wasn't price...it was performance. Just because you guys feel GM Spec oil is good enough for them it's good enough for you...that's fine, this is America and it's your car. But, let us you same fellas apply that analogy to those GM Spec OEM Pirelli Run Flat tires that you all refer to as "run craps". Hey, it's the OEM brand,spec and size...but you guys choose to run tires that put you in a situation that is downright scary by not having a spare. And who says those tire are better? Have you all compared lap times against them?...:thepan:

All I'm sayin' is cut us a break...you run what you run,I run what I run,they run what they run... no reason to rag on us for runnin funny oil in our cars (which is clearly superior!).:shhh:

And I use ZAINO Car Polish, too!(blah!)

inurok
07-20-09, 08:36 PM
^^I was just kidding. That was my poor attempt at sarcasm I guess :(

jwall09
07-23-09, 01:14 PM
BTW, what size wrench will i need to take out the drain plug?

Florian
07-23-09, 06:15 PM
I think its 10mm....


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