Who remembers Green GC 0w-30?

Joined
Aug 20, 2003
Messages
1,467
Location
ottawa
Back when I first joined BITOG, green GC (German Castrol) 0w-30 was all the rage, I remember a good portion of the posts being on that subject. I was in my early 20's back then, and if I wasn't out at the bar or otherwise living up my 20's, I was dutifully looking for GC and super excited when I came across some. Any road trip involved looking for new Autozones I hadn't been to and scouting for the magical green elixir. I remember the Denver metro area being a gold mine-- I used to visit my cousin in Aurora a couple times a month, and in the span of a month or two, I probably visited most every AZ there within a 30 mile radius and procured a good size stash of the stuff. I never did find any at the local Autozones (Colo Springs). It was always disappointing to come across the yellow label US made 0w-30, and it was then that I learned to read date codes and was shocked how long some 0w-30 sat on the shelf. It wasn't a very popular grade at the time, probably still isn't.

Anyone still have any? I thought pouring out green motor oil was the coolest thing. I haven't seen the oil mentioned in a long, long time.
I remember the green gumi bear juice.
Tried 1 oci....
Wish I bought more
 
Joined
Apr 19, 2010
Messages
13,647
Location
Frisco, TX
I remember it well, though I suspect it has long-since been surpassed by more modern formulations. I think at one point I had about 15 bottles of it but used it all up.
 
Joined
Nov 29, 2021
Messages
2,816
I remember it well, though I suspect it has long-since been surpassed by more modern formulations. I think at one point I had about 15 bottles of it but used it all up.
It always struck me as something with a high HTHS, which of course means on the thicker side, that may not have been THAT good in the cold.

I could see how it would make an engine run smooth, I feel there is a correlation between HTHS and fuel economy, given everything else equal, such as, long highway trips on cruise control.
 

92saturnsl2

Thread starter
Joined
Mar 2, 2004
Messages
3,367
Location
Kentucky
I think the rule of thumb is lower HTHS = greater fuel economy and vice versa, someone correct me if I'm wrong. But given that a good number of car manufacturers specify a minimum HTHS, I have to assume > HTHS offers better protection to a point, but with a fuel economy tradeoff. That's sort of a crude blanket statement that I'm sure has exceptions to the rule.
 
Joined
Dec 26, 2005
Messages
21,222
Location
Upper Midwest
It always struck me as something with a high HTHS, which of course means on the thicker side, that may not have been THAT good in the cold.

I could see how it would make an engine run smooth, I feel there is a correlation between HTHS and fuel economy, given everything else equal, such as, long highway trips on cruise control.
It had a 0W winter rating how can it not be “that good in the cold”?

The fuel economy hit would be truly minuscule compared to another 30-grade oil.
 

92saturnsl2

Thread starter
Joined
Mar 2, 2004
Messages
3,367
Location
Kentucky
It had a 0W winter rating how can it not be “that good in the cold”?
Just because an oil can flow at extremely cold temperatures does not necessarily mean it’s “better” or thinner at cold temperatures. Most 5w30 oils are thinner (or more accurately, don’t get as thick) at the normal cold temps that most people experience than a 0w40 or a euro 0w30.

Lots of folks make the mistake of assuming that a 0w oil is the end all, be all for winter weather. Look up viscosity difference at various temperatures and you’ll realize what a bad assumption that is.
 
Joined
Nov 29, 2021
Messages
2,816
It had a 0W winter rating how can it not be “that good in the cold”?

The fuel economy hit would be truly minuscule compared to another 30-grade oil.
I would agree with 92saturnsl2's post on this.
Just because an oil can flow at extremely cold temperatures does not necessarily mean it’s “better” or thinner at cold temperatures. Most 5w30 oils are thinner (or more accurately, don’t get as thick) at the normal cold temps that most people experience than a 0w40 or a euro 0w30.

Lots of folks make the mistake of assuming that a 0w oil is the end all, be all for winter weather. Look up viscosity difference at various temperatures and you’ll realize what a bad assumption that is.
My visit to High Performance Lubricants and looking at measures of the J300 spec in depth also lead me to believe that 5Ws can in fact flow better than 0W depending on their composition and if the temperature is above -25°C.

Is not the be-all, end-all is right, how would GC stack up.

imgf000008_0003.jpg
sae-j300-engine-viscosity-table.jpg
 
Joined
Dec 26, 2005
Messages
21,222
Location
Upper Midwest
Flow is nearly irrelevant. The only flow the oil has to do is to the oil pick up tube and not gel under shear. Winter starting is about cranking and pumpability and yes a thinner oil is better in terms of cranking. But if your battery is so close to the hairy edge that it cannot start your engine between two different 30-grade oils then you’ve got a problem with the starting system not the oil. An oil with a 0W winter rating will “flow” better under very low temperatures to the pump to be pumped than a corresponding oil with a 5W winter rating. If it didn’t then it would be a 5W rated oil. Likewise if some oil with a 5W winter rating is better at cranking and pumpability then it will be labeled as a 0W oil unless the blender is deviating from SAE J300.

Flow is not the primary technical concern in cold weather starting despite people trying to make it so.
 

92saturnsl2

Thread starter
Joined
Mar 2, 2004
Messages
3,367
Location
Kentucky
Flow is nearly irrelevant. The only flow the oil has to do is to the oil pick up tube and not gel under shear. Winter starting is about cranking and pumpability and yes a thinner oil is better in terms of cranking. But if your battery is so close to the hairy edge that it cannot start your engine between two different 30-grade oils then you’ve got a problem with the starting system not the oil. An oil with a 0W winter rating will “flow” better under very low temperatures to the pump to be pumped than a corresponding oil with a 5W winter rating. If it didn’t then it would be a 5W rated oil. Likewise if some oil with a 5W winter rating is better at cranking and pumpability then it will be labeled as a 0W oil unless the blender is deviating from SAE J300.

Flow is not the primary technical concern in cold weather starting despite people trying to make it so.
Go stick a bottle of your favorite 5w30 resource conserving oil in the freezer along with your choice of 0w30 Euro (higher HTHS like an ACEA A3 rated) or 0w40. The 5w30 will be less thick almost every time.

At 0 degrees, I would prefer the thinner oil, maybe that’s just me.

Somewhere around -25F (just guessing, but that’s probably close), the lines cross and you will have similar viscosity between the two, which favors 0w30 the colder you go, but I don’t start my cars at those temperatures.

That’s assuming the 5w30 in question doesn’t meet the requirements of a 0w30, which many do, even though they are labeled 5W.
 
Last edited:
Joined
Nov 29, 2021
Messages
2,816
I turn the key and go with frost still on my windshield, let my car shift into 2nd gear on the first road distance to the stop light, sometimes I catch the light sometimes I don't, and I turn the heater on and off and in 5 minutes it is beginning to turn warm, 10 minutes is fully warm if done correctly. I have one stop sign and my car windshield is defrosted before I get to the 2md light, about 10 miles away. It was 28 degrees this morning, my in car temperature sensor registered 24 degrees on the road (light frost. Not hard frozen, which would have been a little bit more difficult to navigate) and during all this time of measures of coolant warming up, we have the oil.

I believe my oil was fully circulated from almost the moment, probably about 30 seconds past and before the first light on that short stretch of road, when I let my transmission get into 2nd gear (25 to 30mph LIGHT throttle but about 3000RPMs 10 seconds after turning the key,) I don't think my conditions were cold enough to warrant a 0W. I'm running 5W-30 at this time, basic $3.50 a quart oil, nothing special nor exotic. The stuff that used to be labeled conventional.

If I needed a 0W oil, I'm not sure I would do things exactly the same, it also has not gotten colder than 22 or 24 degrees this year, maybe dipped to 18 overnight, this is not cold, folks.
 
Joined
Dec 26, 2005
Messages
21,222
Location
Upper Midwest
Go stick a bottle of your favorite 5w30 resource conserving oil in the freezer along with your choice of 0w30 Euro (higher HTHS like an ACEA A3 rated) or 0w40. The 5w30 will be less thick almost every time.

At 0 degrees, I would prefer the thinner oil, maybe that’s just me.

Somewhere around -25F (just guessing, but that’s probably close), the lines cross and you will have similar viscosity between the two, which favors 0w30 the colder you go, but I don’t start my cars at those temperatures.

That’s assuming the 5w30 in question doesn’t meet the requirements of a 0w30, which many do, even though they are labeled 5W.
If it’s an SAE grade and it meets the performance requirements for a 0W rated oil then it must be labeled as a 0W, it cannot be labeled as a 5W.

And as far as an ad hoc freezer test to supersede an actual real-world performance test, no thanks. I don’t base oil decisions on YouTube videos. You’re right about where the viscosity graphs cross but my whole point in this thread was directed to the notion that the GC product “wasn’t that good” in the cold. Again if you’re really struggling to start the engine “in the cold” with that oil as opposed to another 30-grade your problem isn’t the oil.
 
Joined
Nov 29, 2021
Messages
2,816
If it’s an SAE grade and it meets the performance requirements for a 0W rated oil then it must be labeled as a 0W, it cannot be labeled as a 5W.

And as far as an ad hoc freezer test to supersede an actual real-world performance test, no thanks. I don’t base oil decisions on YouTube videos. You’re right about where the viscosity graphs cross but my whole point in this thread was directed to the notion that the GC product “wasn’t that good” in the cold. Again if you’re really struggling to start the engine “in the cold” with that oil as opposed to another 30-grade your problem isn’t the oil.
Those YouTube freezer testers don't seem to understand that oil doesn't flow down with gravity at start-up, It has to flow up from the pan.
 
Joined
Dec 26, 2005
Messages
21,222
Location
Upper Midwest
Those YouTube freezer testers don't seem to understand that oil doesn't flow down with gravity at start-up, It has to flow up from the pan.
It’s pumped up from the pan. It does have to flow to the pickup tube however and that’s an important aspect of the winter rating and what drove a revision to SAE J300 back in the late 80s.
 
Joined
Nov 29, 2021
Messages
2,816
It’s pumped up from the pan. It does have to flow to the pickup tube however and that’s an important aspect of the winter rating and what drove a revision to SAE J300 back in the late 80s.
Thank you, and was just going to ask you if GC cold flow - sorry, Winter number performance was independent of API SL, or good for API SL, this 0W vs 5W designation. High Performance Lubricants did show me their equipment as well as telling me about MRV rating, the cold pour point until which it absolutely just freezes.. but MRV wouldn't affect when it gets pumped up from the pan, right?

Inverse/opposite, pump vs pour, my question is two-part, 1. Was this the same in API SL as per GC oil and has it changed since 2. Does one have anything to do with the other, this in depth exploration of the Winter number, other factors. ?
 
Top