GC Oil

While I like open-ended questions, this is rediculous.

GC may stand for:
Gordon College (Rawalpindi), Pakistan, A Former Christain College.
GC, an SI symbol for gigacoulomb, for electric charge equal to 109 coulomb
GC, a Unified Soil Classification System symbol for clayey gravel
GC, the IATA code for Gambia International Airlines
GC (character), a fictitious cat on 1980s Mexican television.
Government College University Lahore, Pakistan
Gabriel Centaurio
Galactic Cowboys, a metal band.
Game Boy Color, made by Nintendo.
GameCentral, a cult Teletext-page.
GameCube
Games Convention
Gaming convention
Garbage collection (computer science)
Garnier Corporation
Gas chromatography (Gas-liquid chromatography)
Gay Cunt, Australian youth slang, opposite of MC, Mad Cunt
General Catalogue (astronomy)
General Classification, the aggregate placing in a multiple stage cycling race.
General contractor
General counsel
George Carlin
George Cross
Georgia Central Railway, a class III railroad in Georgia, USA.
Germinal center
Gliomatosis cerebri
Glivenko-Cantelli
Global Catalog
Global citizenship
Global Community
Global Creations, a U.S.(Oregon)media engineering firm
Global Crossing
Glucocorticoid
God Consciousness
Gold Coins
Goldbach's conjecture
Good Charlotte
Goose Creek (South Carolina)
Goshen College
Gran Canaria
Grand Carnival, a Korean minivan built by Kia Motors.
Grand champion
Grand Cherokee
Grand Concourse
Graphics calculator
Graphics context (X11)
Grasshopper-Club, also GCZ, a football club from Zürich
Great circle (navigation)
Green Card
Green Clan
Greensboro College
Greenville College
Grilled Cheese
Ground control
Group Captain (Royal Air Force)
Guanine-Cytosine (genetics)
GC-content (genetics)
Guardia Civil (Spain)
Guidance counselor
Gurkha Contingent of the Singapore Police Force

(Thank you, wikipedia.org.)

 

<div class='quotetop'>QUOTE(Bill Merchant @ Apr 1 2007, 06:06 PM) [snapback]416144[/snapback]</div>

Bill, U gOt 2 MuCh TiMe oN yOuR hAnDs.

 

Google is your friend:

eBay



<div class='quotetop'>QUOTE(ServoScanMan @ Apr 1 2007, 04:47 PM) [snapback]416168[/snapback]</div>

I just did a servo scan on wikipedia.org for GC. I had no idea what the OP meant. I think you got a flakey shift key...

 

Gosh, you mean not everyone knows about GC (or "German Castrol")? This moniker apparently first appeared back in 2003 over on Bobistheoilguy.com (BITOG, where I'm an admin, btw). Most of the Castrol Syntec line is domestically produced, but with two exceptions. One is the 5w-40 grade, which is made in Belgium, and not often seen in US stores. The other is the 0w-30 grade, which from late 2002 until the present, is imported from Germany.

This stuff has a complex history. Up until late 2002, there was a domestically made 0w-30. It came in a bottle with yellow highlights (particularly the grade, outlined in yellow), and has date codes stamped on the bottom of the bottle reflecting the 2002 and earlier vintage. From late 02 until very early 2005, Castrol bottled the first version of GC, which had a startling, almost flourescent green hue to it as it pours from the bottle. It's also pretty green when viewed through a glass container in natural light (but looks brown with a camera flash). In early 2005, Castrol apparently tweaked the formula, as the green color went away, and the newer product looks more conventional.

So what's so special about the stuff? Not just the early GC's color. It seems to produce fantastic used oil analysis results in almost every engine it get put into. There are exceptions, but almost always, this stuff performs wonderfully.

It's also a widely misunderstood oil. Most people initially assume it's "thin", mistakenly focussing on the "0w" part of the grade. Actually, at operating temps, it's thicker than most 30 wt oils, and tests at 12.1 centistokes at 100*C. That makes it very nearly a 0w-40.

A couple years ago, a bunch of us over on BITOG got together, pitched in, and had a Gas Chromatograph test run on some green GC. Unlike the rest of the Syntec line, it's not a Group-III "hydrocracked" oil (which are debatably not "synthetic" at all). It is a PAO and ester combination.

Personally, I hoarded a large supply of the stuff when the green started to get scarce. It's in my Prius right now, and it runs very nicely. Despite the thicker viscosity, I'n not now seeing any mpg loss.

GC is getting scarce in some places. In the US, it is sold almost exclusively at Autozone stores (some others like NAPA can order, apparently). In Canada, Walmart carries it too. If you can find it, try it -- it's a really superior oil.

 

ekpolk,
Other than GC and Amsoil, are there any other PAO and ester combo engine oil out there?

I'm currently using Mobil 1, and I've read that they changed their formula to Group III, which doesn't justify the cost. Please correct my info if I'm wrong.

Scott

 

Scott:

Yeah, I think that's about right, except that the Mobil-1 thing is probably more compicated than a simple switch to a predominantly G-III base.

Ready for a headache? Have a look at this: Exxon-Mobil Patent App. As you can see when you scroll down, reading patents (and applications) is anything but entertaining.

I've plowed through most of it, and while you can't draw definite conclusions about any one M1 product, I do think you can make some general inferences. Most importantly, it looks like what they're doing in most grades is mixing G-III, IV, and even V; and are adjusting the mixture depending upon product (std M1, EP, HM, etc) and vis grade. At least one grade, 0w-40, would appear to remain a "pure" G-IV, V mixture, with no III, though I may have missed some others by not sifting through all the possible inferences.

So a tentative "bottom line" would be that most grades and flavors of M1 are not "straight" G-III products, but they contain a healthy dose thereof; while at least one grade is still a "pure" example of a no G-III "synthetic".

Still watching for more info.

 

Thanks ekpolk for your information!

Holy cow that's lots of stuff I don't understand in that link....

I'm looking for some good FULL synthetic oil that I can use for extended drain interval after my warranty is up. Any recommendations?

TIA!

 

<div class='quotetop'>QUOTE(ScottY @ Apr 3 2007, 03:24 PM) [snapback]417214[/snapback]</div>

Scott:

Yep, that thing is a mind bender. A couple thoughts. First, the debate about M1's performance vs it's true genetics rages on. There is a strong argument that the whole concept of "synthetic" has become warped and overbroad as to now be almost meaningless. As hard as it can be to swallow (for me too), it is true that unless you're talking about a plant-based ester, they all came out of an oil (or gas) well originally ("traditional" PAO is made from ethylene gas...). But that said, M1 is too pricey (IMO) for what it is. XOM is pricing on marketing and reputation, and you can have just as good for less.

Anyway, for what you're describing, you're probably looking at one of the Amsoil choices, TSO (the S2k 0w-30), ASL (the mainline 5w-30), or perhaps even HDD (the HD diesel 5w-30, which also seems to do well in gas engines). If you don't want a G-III, don't order the "XL-7500" Amsoil products as that's what they are. BTW, I'm not an Amsoil dealer...

 

ekpolk,
Thanks again for your insight. I'll give Amsoil a try, follow up with UOA of course.

CapeMayAl,
If you are following the regular drain interval (5k miles), the OEM Toyota filter should be good enough. I bought mine on ebay, 10 for $35. You can't beat that price.

If you want to extend your drain interval, you might look into M1's extended performance filter. It's taller than the Toyota filter, and they claim it will last 15k miles when used with their extended performance oil.

Amsoil also make oil filter, the Ea Oil filter. They claim it will last 25k miles if used with their oil.

I do not have any data backing those up, they are all manufacturers' claims. This is when UOA is useful.

If you are interested to learn more about filters, this website might be helpful, http://minimopar.knizefamily.net/oilfilterstudy.html

 

<div class='quotetop'>QUOTE(CapeMayAl @ Apr 4 2007, 08:13 PM) [snapback]417912[/snapback]</div>

I like the K&N HP-1003, but it's expensive (~$12 at Autozone, slightly more or less in other places). My oil analysis guy swears by the new Amsoil EaO filters. He feels that they offer the best combination of flow and fine filtration.