Castrol 5W50 in a 1ZZ-FE

[ekpolk]

I realize it's not the best example (because of how easy its engine is on oil), but my wife's Sequoia is out of wty, and I've run the 0w-30 GC in it for 13 months and a tad over 10k miles. UOA is posted here, and the oil was still doing fine. I suspect this engine will last a very, very long time on its current diet. My G35 is a bit harder on oil, but from the looks of current UOA, 10k is quite do-able -- after the wty is up, also on GC.

I wouldn't trust that dealership either. I'm lucky, I've got good ones, but many dealers do this sort of thing -- and when something goes wrong, they will (or the mfr will) spend the big bucks to get a precise read on the vis in an attempt to cut you loose.

 

[the_oil_dealer]

that engine is a little Hino truck engine, I'd say youre fine with it in there!

 

[kev99sl]

ekpolk:

To your point, one could indeed just as easily say "why bother" as "why worry": They're probably both valid. I can't speak to this particular application, but can only point to my 99 Saturn, a 95 Civic, a 95 Integra, two Escorts (one 91 and the other 93), a 90-something Tempo, and a 91 Tercel: all well in excess of 150,000 miles, all running Xw-40 or Xw-50 weights year-round in said Chicago weather.

For my part, the switch to Castrol 5w-50 was precipitated by leaking seals that weren't fixed by several Auto-RX cycles, and a consumption rate of 2 quarts/3000 miles. The car was steadily ramped over its life from 5w-30 to 5w-40 and finally 5w-50. Lowest rates of consumption and minimal leaking with the Syntec. Is the oil thinning out? Maybe. I doubt it. I've never pulled an analysis, but all the UOAs I've seen of Syntec 5w-50 would lead me to believe it's holding its viscosity just fine.

As to your comment about manufacturers' recommendations, yes, I am suggesting they're worthless. Well, one caveat: in the U.S. at least, I don't believe they're worth the paper they're printed on. Will the suggested weights ruin an engine? No, I don't believe running a thin oil will do any more or less harm in a modern engine than running a thick oil. But do those recommendations really have anything to do with the engineering specs of the engine? I don't believe it. Has more to do with CAFE and selling a low sticker MPG than anything else. As I've said multiple times here before, one need only question why identical motors in identical cars suddenly go from requiring 50 and even 60 weight oils in European countries of similar climate to 20 or 30 weight mid-way across the ocean. Are we starting to see the change in European and Asian cars? Yes, but again it's a case of "what they can get away with," not "what's best for the car." The same great minds are giving us cars with electric water pumps, no dipsticks or temperature gauges, 100,000-mile spark plugs, and pressurized braking systems that brake no better than standard but require three years of doctoral study and a willingness to sacrifice all the fingers on one hand in order to self-service.

 

[ekpolk]

Kev:

I don't really disagree with what you're saying, but I'm still concerned about at least one issue: warranty problems. As I've often preached here, mere use of a non-spec product (oil or otherwise) does not void a wty at all, it will nevertheless hand the mfr something to use against the customer. I see that your car is clearly beyond wty, so not an issue for you, but for many of us, the prudent course is to stay on mfr recommended products, at least until they can't use our preferences against us.

 

[ChemicallyChargd]

Dr.t says a 40 or 50 at is better than ANY 30 wt, you can say that with out specifying a temperature. And it seems you may not understand that your oil pump only pump so much, it's fixed, when you dump in a thicker oil, all you do is lower the rpm your oil pump reaches full flow capacity, and any rpm above that you aren't getting any more oil (getting the same flow @6000 as you were at 2500) and at an oil temp of 235 I'll take a 30 over 40 or 50 anytime, I'll get more flow, flow lubricated not pressure, an increase in pressure from a thicker oil is telling you the pump is just reaching full flow sooner. No that's not good, either, the only reason these heavy oils even still exist for gas engines is because there's still people ignorant enough to buy them. (Note, ignorant doesn't mean stupid, just means you don't know any better) do you think if heavy oils were better some of the hottest, highest revving engines in the world would b using them, well, they arent, they being formula1 use 10w oil, it flows much more at the same rpm than heavier oil, this higher flow keeps moving parts totally drenched in oil instead of starving for it because the thicker oil cannot move through the very small passages near as fast. Do a BITOG search for "motor oil 101" by Dr. Haas, by far the best oil article I and many others have read, I've actually read it several times because very sadly a more detailed article for us that want all the juicy hard to understand technical bits Haas purposely left out so more could understand the read.
-srv

 

[ChemicallyChargd]

You can't** say that one weight is better than ANY other without specifying a temperature, because I assure you at -50 degrees below your 40 or 50 won't even pump, whereas the 0w-30 is still just fluid enough to start an engine. Clearly in this condition the 30 is far better isn't it? At 302 F, which is why you use a thicker oil right, you think thinner oil won't be thick enough at a very high temp, at 302 the difference between a 30 and 50 is actually very small, and the 30 being only very slightly thinner, the hotter it gets, the smaller the difference is in viscosity, but the lighter oil at 302(150C) will always outflow the heavier keeping the engine cooler. Not only that your oil pump working harder than it has to is generating more heat, the engine not getting as much flow generates more heat, so a thicker oil really increases your temps all around, so enjoy.
-srv

 

[OVERKILL]

Originally Posted By: ChemicallyChargd
You can't** say that one weight is better than ANY other without specifying a temperature, because I assure you at -50 degrees below your 40 or 50 won't even pump, whereas the 0w-30 is still just fluid enough to start an engine. Clearly in this condition the 30 is far better isn't it? At 302 F, which is why you use a thicker oil right, you think thinner oil won't be thick enough at a very high temp, at 302 the difference between a 30 and 50 is actually very small, and the 30 being only very slightly thinner, the hotter it gets, the smaller the difference is in viscosity, but the lighter oil at 302(150C) will always outflow the heavier keeping the engine cooler. Not only that your oil pump working harder than it has to is generating more heat, the engine not getting as much flow generates more heat, so a thicker oil really increases your temps all around, so enjoy.
-srv


Except the oil at 150C is the exact reason that the HTHS measurement exists. And that small difference is significant, as it may mean the difference between a wiped bearing and engine failure or an eventless trip around the track.

This is the reason the Euro marques spec an oil with an HTHS >=3.5cP for example.

I don't know what the HTHS is for the oil the OP is referencing, but if we say, for the sake of argument that it is ~4.5cP and your 0w-30 reference oil is 3.1cP, that is an extremely significant difference, even though it doesn't have the "wow" factor of being in the thousands like when we compare CCS or MRV.

And oil pumps are positive displacement. So unless you are on the bypass (unlikely) the engine is getting just as much oil with 5w-50 in the pan as it is with 0w-30. What you'll observe is higher oil pressure relative to the increased resistance in the system.

This is the reason that many high performance, high power-density engines spec heavier oils from the factory. Ferrari doesn't spec 10w-60 for track use because they are stupid. Ford doesn't spec 5w-50 for the BOSS 302 or GT500 because they are incompetent....etc.

 

[aquariuscsm]

How close is the actual viscosity of GTX 20W50 to Syntec 5W50?

 

[A_Harman]

Holy thread resurrection, Batman!

 

[uart]

Originally Posted By: A_Harman
Holy thread resurrection, Batman!

That's for sure.

Reviving an old thread to provide an update of events is one thing, but doing it just to reply something someone said eight years ago, well that's pretty silly.

 

[Garak]

Originally Posted By: ChemicallyChargd
You can't** say that one weight is better than ANY other without specifying a temperature, because I assure you at -50 degrees below your 40 or 50 won't even pump, whereas the 0w-30 is still just fluid enough to start an engine.

I realize there was a search going on for one of ekpolk's threads. However, I'm not exactly sure why one is arguing with people who haven't posted since 2009 and 2011, particularly on a seven and a half year old thread.

 

[supercity]

Originally Posted By: ekpolk
Bad for several reasons. 5w-50 is likely loaded with vis index improvers. I'll assume the current VIIs are better than the ones of the not-too-distant past that sludged so many engines, but even so, if they're not needed, why have them in there???


I don't understand why there is such hate for 5w50 "because they are loaded with VII" yet 0w40 with an equal or higher VI are so loved.

 

[aquariuscsm]

Originally Posted By: supercity
I don't understand why there is such hate for 5w50 "because they are loaded with VII" yet 0w40 with an equal or higher VI are so loved.


^^This. I wonder this very same thing.

 

[Garak]

I would hope that shear stability has improved since 2005.