Castrol GTX: The sleeper oil?

[The Critic]

With the limited number of recent, Castrol GTX UOAs we have in our database here at BITOG, the GF-4 (and esp. the SM) versions of this oil has worked extraordinarly well for extended drains by providing excellent TBN retention, especially in turbocharged engines such as the Audi 2.7T and the turbocharged, Subaru 2.5L that is present in the Legacy GT.

Here are some examples:
Castrol GTX 5w-30 SM/GF-4 @ 4906 miles in a 2.5L, Turbocharged Legacy GT

Castrol GTX 5w-30 @ 10,831 miles in a 2.7L, Turbocharged Audi A6

Castrol GTX 5w-30 @ 7,856 miles in a 2.7L, Turbocharged Audi Allroad

Castrol GTX 5w-30 SM/GF-4 @ 7,200 miles in a 2001, Infiniti I30

Thoughts? Comments? Agree/Disagree?

Fire Away

,
Michael

 

[Thatwouldbegreat]

I wouldn't be suprised Michael!

I always had good luck over the years with Castrol GTX. And we all know why lots of oil nuts dropped Castrol*

Castrol seems to to have lots of smart guys formulating oils and mixing additive packages...its the marketing and legal guys who put me off Castrol.

But, I'll bet its the marketing and legal slime who make the bucks for Castrol...not the scientifically and engineering minded guys who try and make good product.


[ I am using Castrol Syntec 0W-30 GC and Transynd ]

 

[G-MAN]

I think if you look at the two Audi UOAs you've listed you will find that there is only speculation that the oil used is Castrol GTX. I seriously doubt it is.

 

[The Critic]

quote:

---

I think if you look at the two Audi UOAs you've listed you will find that there is only speculation that the oil used is Castrol GTX. I seriously doubt it is.

---

The additive levels look very much like a GF-4 formulation, and the viscosity read on the low side for one of the UOAs. Synthetics rarely shear, they often show the effects of oxidation related thickening when run to such a high interval.

 

[m2200b]

quote:
I think if you look at the two Audi UOAs you've listed you will find that there is only speculation that the oil used is Castrol GTX. I seriously doubt it is.

I'd drop the Audi Turbo from your GTX user list.
Dealer oil has Too much moly for GTX.

 

[TallPaul]

After seeing this thread I sure won't buy any GTX.

 

[Dad2leia]

It's all in the marketing hype.

 

[Triple_Se7en]

TallPaul Quote:
After seeing this thread I sure won't buy any GTX.

Well I guess Havoline is no good too Paul... it has the same HT/HS. BTW.... what dino in 5W-30 has a 3.5 HT/HS????????

==============================================

Quote Dad2leia:
It's all in the marketing hype.

Well I guess you haven't been reading the Used Oil Analysis board here. There are a few very nice Castrol GTX UOAs there recently.

 

[Buzzsaw]

GTX can't be bad. Before I met my wife she did 10K drains on GTX in her Monte Carlo and the car is still being driven by one of her friends daughter.
Edited to add that my wife was putting approximately 600 miles a week on the car with her commute so most of the miles were highway miles. she sold the car with 230k on the odometer.

 

[TallPaul]

A couple from the Oil Tech Data sticky thread above:

Pennzoil coventional 10w30 = 3.2
Pennzoil HM 10w30 = 3.4

Valvoline told me that both Durablend and AllClimate 10w30 were 3.0, whereas Maxlife 10w30 is 3.3

Redline 5w20 has an HTHS of 3.3! That's why I have it in the '92 3.0 Aerostar right now.

 

[boxcartommie22]

paul, yo uknow iam a redline nut but you should also try motul 300v chrono 10w40 oil..its a double ester and iam using 1 qt. with my redline 10w30..i think you will be pleased

 

[NewGuy]

Tallpaul...The GTX in that thread was a 5W20 version, not a 10W30. It looks like an apples and oranges comparison. Am I missing something?

 

[TallPaul]

The thread I linked had both 5w20 and 10w30. Unfortunately the data was run together and you would not see the 10w30 on a cursory look.

I probably should look into Motul. I'm sure MBGV8 would agree on that too.

 

[NewGuy]

TallPaul.....my apologies. I see what you are saying. I did confuse the data. That HTHS surprises me, but I have had good results with Castrol GTX.

 

[Drew99GT]

I could be wrong, but many of those numbers listed by Castrol are the max/min/limits for each grade, such as the HT/HS viscosity. It seems to hold it's viscosity better than most other conventional oils ON AVERAGE. It's good oil, and I'd have no qualms about pouring it in my engine. Shoot! I'd even use Valvoline!

 

[TallPaul]

That's OK NewGuy. It really was hard to see.

Yep, the minimum for a 30 weight is 2.9 according to the API Engine Oil Classification chart. They must have quoted the minimum, which is not very smart from a marketing perspective. NOACK is pretty decent anyway.

Anyway, I just bought 19 bottles 10w40 Castrol GTX Start Up on clearance for $1.40 each and am pleased to see it is 15.9 cSt 100C viscosity. I have a call in to Castrol to get the HTHS on this stuff for me. Will post if they come through with it.

 

[lobo11]

A lot of people on this board bash Castrol and Valvoline oils. For this reason I usually try and look at the UOA's of these oils to see why, and to be honest both seem to perform very well in general. I wouldn't hesitate, and don't, to use either of these oils.

 

[AndyH]

quote:

---

Originally posted by LarryL:
As soon as GC developed a great reputation it appears that the bean counters dumped it for a new formula.

---

How do you know the "bean counters" forced the switch from the "green" GC to "gold" GC? Seems like total speculation on your part, IMHO.

 

[sky jumper]

well, if the VI of GC dropped from 179 to 166 with the switch (as has been purported on bitog) then it surely wasn't the engineers that forced the change. I'll bet gold GC is the same grp III shtuff as regular syntec. we need another z oil report!

 

[G Peen Jr]

> Castrol called me back today and told me
> the HT/HS on Castrol GTX and GTX Start UP
> 10w40 is ........... 2.9!

As you said, this is the minimum for the group. Castrol only gives out min or max numbers, which do not correspond to the actual.