German Castrol on a WRX turbo in the Texas summer?

[DrivinWest]

Hey all,

The previous owner of my 2005 Saab 9-2X Aero (mechanically identical to a 2005 Subaru WRX wagon) used Mobil 1 religiously. From everything I've read here and on NASIOC, Subaru engines consume absurd amounts of Mobil 1. As a result, I decided to change to German Castrol based on all the positive comments I've seen here. I'm approaching 5K miles on that oil and need to change it shortly.

My concern is using a 0w-30 oil in the Texas summer. It gets pretty darn hot here and I'd hate to run anything too thin, especially in a turbocharged car.

Your $0.02 is most welcome.

 

[Quattro Pete]

GC should have no problem - it is far from "thin". With that said, a lot of turbo Subaru owners here seem get really good results with Shell Rotella T 5w-40.

 

[StevieC]

Originally Posted By: DrivinWest
Hey all,

The previous owner of my 2005 Saab 9-2X Aero (mechanically identical to a 2005 Subaru WRX wagon) used Mobil 1 religiously. From everything I've read here and on NASIOC, Subaru engines consume absurd amounts of Mobil 1. As a result, I decided to change to German Castrol based on all the positive comments I've seen here. I'm approaching 5K miles on that oil and need to change it shortly.

My concern is using a 0w-30 oil in the Texas summer. It gets pretty darn hot here and I'd hate to run anything too thin, especially in a turbocharged car.

Your $0.02 is most welcome.


The 0w30 GC is a heavy 30 weight and more close to a 40wt anyways so I think it would work just fine with your Turbo, so long as your not driving spiritedly all the time and just the occasional thromp on the gas here/there creating boost and not keeping the turbo red-hot for extended periods of time.

The "0" relates to the flow when cold and doesn't in anyway make the oil "Thin" at operating temperature. Theoretically a 0w30/5w30/10w30 etc. are all pretty much the same at operating temperature, but flow differently at cold temperatures.

Nice car!

and

 

[Audi Junkie]

It's a good visc for a new engine or for winter. In an engine that's been abused with Mobil 1 30 weight and in your climate, a 5w-40 might be in order. Save the GC for winter, 5w-40 is quite poor near 0f.

 

[Quattro Pete]

Average low in January in Austin is about 40F.

 

[bretfraz]

I think GC would work great in that motor. As others have said, its a bit on the "thick" side, almost a 40W before shearing down. By comparison, most Mobil One xW-30's are on the "thin" side of 30W, shearing down close to a 20W after a few thousand miles.

Anyway, give GC a try and see how it goes. Also consider that Rotella T Synth for a future oil change.

 

[ZZman]

If you are worried about your turbo and high heat try Redline.

I don't know why people in warm/hot climates run 0 weight oil.

 

[DrivinWest]

This is some fantastic info. I really, really appreciate it! I'll give Shell Rotella T, etc., a look.

FWIW, I've got ~53K miles on it. I may do a UOA on the GC and see how it fairs against 5K miles on Rotella T.

Thanks again!

 

[gfh77665]

Originally Posted By: DrivinWest

My concern is using a 0w-30 oil in the Texas summer. It gets pretty darn hot here and I'd hate to run anything too thin, especially in a turbocharged car.


I hear ya! I HATE the fact Honda requires a 5-20, even for us Texans. I use it just to stay "in warrenty". I just grit my teeth and hope for the best. FWIT, I use only full syns... and hope they hold up a little better in our heat. Arrgggg.

 

[Captain_Klink]

For the Subaru, I would run Mobile 1 10w30 synthetic. It still has the cold properties of a conventional 5w30, but is reliably shear stable.

For a Honda that requires 5-20, there have not been any rash of engine oil related failures, but if u live in Texas, I would use a 5w30 synthetic mixed 50:50 with a conventional 5w20, or 2qt synthetic 10w30 blended with 2 quarts conventional 5w20, or even just straight 5-30 synthetic.

For a reading of the law, as on the Amsoil site:
Question: Could using a 5W-30, 10W-30, 0W-30 or even a 10W-40 or 20W-50, oil in my vehicle which specifies a 5W-20 oil void my new car warranty?

Answer: Absolutely not. Vehicle manufacturers only recommend using motor oils meeting certain viscosity grades and American Petroleum Institute service requirements. Whether a motor oil is a 5W-20, 5W-30, 10W-30, 0W-30, 10W-40 or 20W-50 (for racing and high performance applications in, for example, a Cobra R Mustang) or even a synthetic vs. a petroleum based oil will not affect warranty coverage. The manufacturer is required by Federal Law to cover all equipment failures it would normally cover as long as the oil meets API service requirements and specifications and was not the cause of failure. In addition, the Federally mandated Magnuson - Moss Act states that a manufacturer may not require a specific brand or type of aftermarket product unless it is provided free of charge. If your dealership continues to tell you that you must use 5W-20 motor oil and or/ a specific brand of 5W-20 motor oil, then ask them to put it in writing. Their position is inaccurate, and, in fact violates existing law.*

 

[ekpolk]

Originally Posted By: ZZman

I don't know why people in warm/hot climates run 0 weight oil.


Why not, if the oil has the characteristics one is looking for? Can you specify an actual, performance-related drawback to using a 0w-something oil in a "warm/hot" climate?

In the Mobil-1 line, the 0w-30 oil is only 0.3 cSt lighter than "mainstream" 5w-30, and exactly the same hot vis as the M1-EP 5w-30 (11.0 cSt). In the Castrol Snytec line, the 0w-30 oil (GC, the subject of this thread) is much, much thicker than the 5w-30 (12.1 vs. 9.7 cSt) or the 10w-30 (10 cSt). In short, for the most part, it's a toss. Now, if you use Syntec, and want a thick 30 for hot weather use, the 0w-30 would actually be the best choice. Just browse our used oil analysis section -- the vast majority of the GC UOAs are stellar in all conditions. I myself used a fill of GC in my wife's Sequoia for 13 months and 10k miles. It could have gone almost another year. And I live in Florida.

For the most part, with modern oils, in the "warm/hot" areas, the 0w portion of the rating is NOT a drawback, it just fades to near-irrelevance.

 

[ekpolk]

Originally Posted By: gfh77665
Originally Posted By: DrivinWest

My concern is using a 0w-30 oil in the Texas summer. It gets pretty darn hot here and I'd hate to run anything too thin, especially in a turbocharged car.


I hear ya! I HATE the fact Honda requires a 5-20, even for us Texans. I use it just to stay "in warrenty". I just grit my teeth and hope for the best. FWIT, I use only full syns... and hope they hold up a little better in our heat. Arrgggg.


Oh come on now, it really is time to relax about the 20 wt oils. I had the fear too, the first time I saw "5w-20" stamped on the oil filler of a new Honda I was looking at back around 2001 or so. We're now approaching the end of the first decade of wide-spread xw-20 oils being spec-ed as preferred (Honda, Ford, now Toyota, and others as well). And we simply aren't seeing the tidal wave of failures everyone feared at first. Sure, there are some engines that "like" heavier oils, but that is purely a function of such things as the design of the oil system, bearing clearances, and so forth. It's NOT because of some inherent flaw in 20 wt oil.

Honda has a reputation as one of the world's best engine makers, they know that's their rep, and they know that it's a priceless intangible. They would not risk that reputation for anything. I'm satisfied that they did their research homework before making the move to 5w-20. And notably, unlike Ford, Honda has never had the need to "counterbalance" the awful CAFE consequences of selling zillions of F-150s and Expeditions.

If you really have a bee in your bonnet about 20 wt in Texas, go ahead and do a UOA or two yourself. Particularly with a Honda, that should put your fears to rest.

 

[440Magnum]

Originally Posted By: DrivinWest
Hey all,

The previous owner of my 2005 Saab 9-2X Aero (mechanically identical to a 2005 Subaru WRX wagon) used Mobil 1 religiously. From everything I've read here and on NASIOC, Subaru engines consume absurd amounts of Mobil 1. As a result, I decided to change to German Castrol based on all the positive comments I've seen here. I'm approaching 5K miles on that oil and need to change it shortly.

My concern is using a 0w-30 oil in the Texas summer. It gets pretty darn hot here and I'd hate to run anything too thin, especially in a turbocharged car.

Your $0.02 is most welcome.



As everyone else has said, there's no downside to a 0w30 compared to a 10w30 when you're talking about modern synthetic oils that can achieve that spread with fewer/better VIIs than it took to make a 10w30 oil 20 years ago.

What I haven't seen is a recommendation for Shell Rotella T Synthetic 5w40. Turbo Scoobiedoos seem to respond EXTREMELY well to it- lots of very good UOAs posted, and lots of good testimonials.

But then, I really don't believe the "consume absurd amounts of M1" nonsense either. If you're looking for a very robust PAO based oil, I would very much consider M1 TDT 5w40. In all honesty its probably a bit better oil than RTS, but significantly more expensive.

I guess there's nothing wrong with "German" Castrol either. I just have a feral anti-Castrol reaction because of their silly advertising campaigns- yes, I know its not rational

 

[ekpolk]

Originally Posted By: 440Magnum
...
But then, I really don't believe the "consume absurd amounts of M1" nonsense either. If you're looking for a very robust PAO based oil, I would very much consider M1 TDT 5w40. In all honesty its probably a bit better oil than RTS, but significantly more expensive.


Good point. I wonder if some of M1's consumption rep might be a result of dated information/oil. Up until a couple years ago, the M1 5w-30 (now of course, we have several flavors in that grade...) was a very "thin" thirty. IIRC, when I joined here five years ago, the PDS said 9.something cSt. Now most of them are around 11 cSt. Not a big difference, but if the Subarus are prone to drink lighter oils, that might be a partial explanation at least.

Originally Posted By: 440Magnum
I guess there's nothing wrong with "German" Castrol either. I just have a feral anti-Castrol reaction because of their silly advertising campaigns- yes, I know its not rational

Hey, the first step toward becoming as rational as Mr. Spock is to see and acknowledge your own irrationality!

I don't care for some of Castrol's business practices either, but I've bought approximately a zillion quarts of green GC in past years. . .



[/quote]

 

[Audi Junkie]

Hmm, the time I spent on an RSX Forum, massive consumption and Mobil 1 5w-30 (as specified on the cap) went hand-in-hand.

 

[ekpolk]

Yeah, but which M1 are you talking about??? There are now several different flavors of just 5w-30 M1. Mainstream, EP, TSUV, etc. And then, of course, there are the 0w-30 and 10w-30 variants, which are, in all candor, pretty similar to the 5w-30 flavors.

If you've had an issue with a particular product from E-M, please specify. On the other hand, general M1 bashing, with no specification of what grade was used, and under what conditions, is worse than unhelpful.

Which variant of M1 5w-30 are all these RSX folks complaining about, and from when?

 

[artificialist]

Originally Posted By: ekpolk
Originally Posted By: ZZman

I don't know why people in warm/hot climates run 0 weight oil.


Why not, if the oil has the characteristics one is looking for? Can you specify an actual, performance-related drawback to using a 0w-something oil in a "warm/hot" climate?

In the Mobil-1 line, the 0w-30 oil is only 0.3 cSt lighter than "mainstream" 5w-30, and exactly the same hot vis as the M1-EP 5w-30 (11.0 cSt). In the Castrol Snytec line, the 0w-30 oil (GC, the subject of this thread) is much, much thicker than the 5w-30 (12.1 vs. 9.7 cSt) or the 10w-30 (10 cSt). In short, for the most part, it's a toss. Now, if you use Syntec, and want a thick 30 for hot weather use, the 0w-30 would actually be the best choice. Just browse our used oil analysis section -- the vast majority of the GC UOAs are stellar in all conditions. I myself used a fill of GC in my wife's Sequoia for 13 months and 10k miles. It could have gone almost another year. And I live in Florida.

For the most part, with modern oils, in the "warm/hot" areas, the 0w portion of the rating is NOT a drawback, it just fades to near-irrelevance.

In addition, if you read the UOA section, 0wXX oils in hot climates have excellent UOA results.

I suspect that 0wXX oils must be made with better ingredients than 5wXX oils.

The other reason GC seems ideal is because it gets used in VW turbo engines without problems, it is proven to take the heat.

 

[ekpolk]

I would hasten to add to my previous comments that I'm no 20 wt Kool-Aid drinker. We have two cars (of three) that are either spec-ed for 20 wt (Camry Hybrid), or back-spec-ed to it (Avalon). Oddly enough, the Prius has it's own TSB that says it's firmly a 5w-30 car (I suspect for dilution issues, but that's another story).

And what do you suppose I'm using at the moment in my 0w-20 Camry hybird? That's right, 12.1 cSt green German Castrol. How can that be, you ask? Well, there is this mysterious comment in the 09 HyCam manual:

Well now, how'z that for creating about 10x as many questions as it answers??? Anyhow, it's hot here now, and I've still got a good bit of green left, so I decided to try it. I think I will UOA it, and then switch back to PP 0w-20, and compare how the two stack up against one another.

 

[gfh77665]

Originally Posted By: ekpolk

Oh come on now, it really is time to relax about the 20 wt oils. I had the fear too, ....


...If you really have a bee in your bonnet about 20 wt in Texas, go ahead and do a UOA or two yourself. Particularly with a Honda, that should put your fears to rest.

Well, my fears STARTED to abate, until your last post, and its underlined wording(above) Arrgggg!

 

[ekpolk]

Originally Posted By: gfh77665
Originally Posted By: ekpolk

Oh come on now, it really is time to relax about the 20 wt oils. I had the fear too, ....


...If you really have a bee in your bonnet about 20 wt in Texas, go ahead and do a UOA or two yourself. Particularly with a Honda, that should put your fears to rest.

Well, my fears STARTED to abate, until your last post, and its underlined wording(above) Arrgggg!


Ahhhhhhh -- we can never do too much thinking -- can we!

On a more serious note, I think, and it's just my opinion at this point, all this points to a rough conclusion to the effect that, in a modern engine, for the vast majority of operating parameters, perhaps all parameters that a normal driver will encounter, a 20 wt will do the job as well, or better, than a 30 wt.

That comment is troubling to me as well, but not for the reason you might think. I'm concerned that they make a totally subjective, unbounded comment about what should be an easy objective call. Afterall, what exactly are "high speed" or "extreme load conditions"? And just what alternative should an owner use if he encounters such conditions?

At the end of the day, this vague statement is essentially worthless, except perhaps a license for oil freaks like us to experiment around. Hey, I'm warranty safe as long as I don't do something truly stupid like traveling to North Dakota in February and filling my car with SAE 60 oil. And even then, I could still claim I was driving at "high speed". . .

EDIT: Oh yeah, also notice the very curious (to me anyway) lack of a TEMPERATURE parameter. Does this caveat apply in Anchorage in January with the same force as it would in Miami in August?