Why I will not use the Green GC

[The Critic]

Why I will not use the Green GC:

1. Availability
2. Weak TBN retention
3. Price

To me, when Mobil 1 0w-40 is avaliable everywhere for $4/quart, especially in a 5 quart jug at WalMart, I don't see why I should run GC. Yes, Mobil 1 0w-40 has a tendency to shear, so in the end, they both end up at roughly the same viscosity.

In addition, they're both Mobil 1 0w-40 and GC are both about the same in the TBN department, if not, M1 may even have the edge.

Both of them seem to produce very good wear. However, GC also has a tendency to thicken up, like it did on Terry's VW in his recent 15K run, and that was even with LC!

Fire Away,
Michael

 

[Mamala Bay]

Well I don't use GC cause there is non here. I like going on a one year oil change. I've had good results with Amsoil so why change a good thing.

 

[LVHospiceRN]

I WILL use GC because, elves aside, it offers another choice, an alternative to Mobil 1. Don't get me wrong, M1 is a great oil and you are right about specs being simular.

I LIKE the "hard to acquire" status of GC, I like the alternative it offers, I like that it is green, I like the excellent wear numbers it has posted, and well, then there is that Elves thing...

darrell
sin city

 

[Bio-T]

My John Deere is green, so it is only fitting that I acquire and use green oil. So GC will get the nod. When there is no green GC for the green machine, it off to Schaeffers green again.

 

[shortyb]

All valid points, guess it may be a matter of personal taste. FWIW I've seen my share of posts about increased noise and M1. Also a few UOAs where the 0W-40 has sheared quite a bit, down to a low 30wt after 5~7K. The GC is very stable but has been known to thicken slightly. Seems to happen with it after 10K or so. Me personally, I'd rather have it this way as opposed to the shearing. Overall, I've seen better wear numbers with GC but we all know how subjective that can be with all the variables. Price? Well I've paid as little as $1 a quart (misread by scanner, love those AZ clerks

) and average alittle more than M1, but for me its worth the extra pennies. IF you can find it, like you said.

 

[fastbear]

I try to use green oil in my old green John Deere, but around this neck of the woods the only green oil is Schaeffers and after a fashion it turns to a dark brown shade. The old 430 likes green juice so it is stuck with Schaeffers for the rest of its natural life.

 

[SSDude]

I did not find the TBN retention of GC to be weak over 10,000 miles in my LS1. In addition, I can still get GC at $3.99/quart. AutoZone will price match. All you need is a competitors coupon. What is important to me is whether an oil will shear over a long run. I guess there will be more GC around for someone else.

 

[Mr Nice]

Has anyone ran Castrol GC past 10,000 miles ??

 

[haley10]

Actually GC was easiest and cheapest to acquire for me. I got most of mine for $3.99 US per qt. at an Autozone just a few blocks away. M1 0W-40 wasn't cheaper for me.

Competition and freedom of choice is a good thing. Each to his own.

 

[SSDude]

quote:

---

Originally posted by LT4 Vette:
Has anyone ran Castrol GC past 10,000 miles ??

---

I believe that there were at least two UOA of GC at 12,000 miles.

 

[bretfraz]

After 6000+ miles my TBN using GC was 4.5. Perhaps some engines are harder on oil than others but a classifying GC as a poor TBN retainer is wrong IMO; I don't see the TBN of M1 or other full synth being much better.

I can find GC just as easily as M1 in my neck of the woods. Price is either exactly the same or cheaper than M1. I don't recall ever seeing a 5qt jug of 0W-40 anywhere, certainly not at the 3 local Walmart's I've been to recently.

For me, (slightly) thicker is better. I get less piston slap with GC than from any oil I've used. I used M1 on a previous car and it was quite noisy on startup compared to GC.

As long as I can find GC locally at a competitive or superior price, I see no reason to use any Mobil oil again unless Castrol completely trashes the formulation.

 

[LVHospiceRN]

quote:

---

Originally posted by bretfraz:
As long as I can find GC locally at a competitive or superior price, I see no reason to use any Mobil oil again unless Castrol completely trashes the formulation.

---

and the elves would never allow that to happen...

darrell
sin city

 

[CONMCK]

My last OCI in the UOA section had a TBN of over 7. That was 6 months, over 5000 miles and mostly winter driving in Canada. That seems reasonable to me for TBN retention.

 

[blupupher]

quote:

---

Originally posted by AndyH:

quote:

---

Originally posted by blupupher:
3. $3.99 if you know how to shop and use price matching.

---

Unfortunately, the price-matching at AutoZone seems to be a bit hit-or-miss. The only local AutoZone in my area that had any decent supply of GC would not price match a Pep-Boys $3.99 Castrol Syntec coupon despite speaking directly with the store manager.

---

Do what I did, go to a store that does price match, but buy 5w-40 or whatever, then go to the one with the GC and exchange them. It kinda ****** the manager off when I did it, because he knew exactly what I did, but screw him, I got my GC!

 

[buster]

One of Mobil 1's strengths is it's TBN retention. Of course that was with the GF-3 stuff. The current SM version is probably on par with GC. I believe the starting baseline TBN is 9 or 10. German Castrol IMO, is a better oil then Mobil 1 0w-40. However, finding it and knowing what the new stuff is presents some problems.

 

[Last_Z]

quote:

---

Originally posted by LT4 Vette:
Has anyone ran Castrol GC past 10,000 miles ??

---

Yes! Look for my wife's Corolla in the UOA section. I think it had 10,040 miles on that UOA.

 

[gudmund]

have done 4 10,000mile samples so far. first 2 with M1 5w30 TBN#s 4.1 & 3.5, third was Amsoil 5w30 TBN 3.9 and the forth was with GC 0w30 TBN 3.3. Am about halfway though a 10,000mile run with the New 'SM' M1 5w30-will be testing it by mid July than will be putting in M1 'EP' 5w30 for at least 10,000miles(maybe 15,000 if it does well.) All 4 of these oils did well with Blackstone stating 'go 12000 next time with each of them' both M1's did show some extra iron over the other two but they both ended up thicking some and I did see some decrease in gas milage with both but not with the M1. Car is a 98 Suzuki Swift 1.3L 16V 4cyl 5sp which has 105+thou on it now. 43/45mpg average overall. My main complain against GC is it is hard to find being the Autozone's around here only have it off and on.

 

[blupupher]

quote:

---

Originally posted by gudmund:
... both M1's did show some extra iron over the other two ...

---

Isn't that kinda normal for Mobil 1?

 

[gudmund]

M1 iron 38 & 47 which Blackstone stated "Iron typically reads higher with extended oil use."
Amsoil iron 10
GC iron 28 all 4 samples taken after 10,000miles each

 

[buster]

"M1 iron 38 & 47 which Blackstone stated "Iron typically reads higher with extended oil use."
Amsoil iron 10
GC iron 28 all 4 samples taken after 10,000miles each"

You would need more of a trend then that though. Too up and down. Many variables could have impacted all those results.