ATF: Amsoil Signature vs Toyota WS vs Idemitsu

Astro14

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Yup, I’ll drive it, service it as recommended, sell it, life goes on.

Just more BITOG neuroticism centered on the belief that one can know the unknowable - namely by looking at ATF you can determine it’s “crap” at 21k miles.
The carefully calibrated eyeball looking at ATF color beats any spectrometer or chemical test, right?
 
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Yup, I’ll drive it, service it as recommended, sell it, life goes on.

Just more BITOG neuroticism centered on the belief that one can know the unknowable - namely by looking at ATF you can determine it’s “crap” at 21k miles.
Don't bother arguing. I basically said the same thing. How can millions of Toyotas go millions of miles on dreaded old-specd out-of-date Dex III, T-IV, and WS?
 
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The oilclub.ru site had a post several years ago about the Idemitsu product. Someone ran some in-depth testing (beyond a typical UOA) and felt it was a very close identical to the Genuine WS.

I have used all 3 products in various U660 transmissions and have never observed any differences in performance.

A fluid pump is essential- you can’t get a quart or funnel in there. I have a two gallon rig that looks like a garden sprayer. I use only ATF in it. You can get the hose from that in the fill plug. It’s a tight space.
I highly recommend one of these units if you own several vehicles with a dipstick-less transmission. It makes the process less painful:


edit: I found the link:
 
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ekolpack

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Daaaaamn, so many great replies here! Thanks fellas!

A few thoughts. Re @rob1715 "if WS is so bad, why do so many 'yotas last so long running WS?" This is a good point and definitely something I considered. I'm inclined to think it comes down to the mechanical design and implementation far more than a marginal improvement in the type of ATF (which is what I'm going for). Toyota seems to be amazing at building the best, most-reliable vehicles in the industry....that's their specialty and nobody is better at this. When it comes to oils/fluids, clearly they do an excellent job here too, but it's not their area of specialty....they're not the best of the best in the world when it comes to making oils. I believe that title goes to Amsoil. I think Toyota makes a cost/value calculation. They buy their oil (or at least the base) from a third party, who has to mark it up, and they need room left for their own markup to dealerships and then a massive markup to the end consumer. If they used super high-end oil with tons of $ in R&D as their base (such as Amsoil), there'd be no margin left. So they make a typical engineering efficiency calculation like all car manufacturers make for every part in every step of the design process that the component in question (in this case, WS oil) is good enough, maybe even very good, while being cheap enough, maybe even very cheap. That's what it seems like to me anyway, as a random internet person with absolutely no understanding of the actual way Toyota Corp works or what criteria they use to make their cost/value calculations ;)

Basically, is Toyota WS good, maybe even very good? Good enough to keep many already very, very well built, well-engineered vehicles going for many thousands of miles? Yes. Are many of these vehicles *cough*Hilux*cough* so good that they could probably run on Canola oil? Yes. Could WS be better? Yeah, I think it probably could? Have there been examples of Toyotas surviving EXTREME torture tests, such as running them with no oil, or on original oil after 100k miles or other such ridiculous things? Yes. So I think that makes the case that why Toyotas last so long is mostly due to mechanical variables, not so much outstanding OEM oils. I think there's room for marginal (not huge) improvement there.

Amsoil is to oil design and manufacture what Toyota is to vehicle design and manufacture. I'm just trying to get the best of both worlds.

Re @Mainia I've heard this kind of thing from several folks in online forums or on reviews (ie. that original OEM fluid or some cheaper fluid was trashed, new Amsoil or other such fluid looked brand new at the next change after 30-50k miles). I notice this is often on newer vehicles after the first fluid change. I'm no transmissions specialist, but could it be that new transmissions have to be worn in? I know this is the case with difs and transfer cases. The fresh gears have to shear off a bit of fresh sharp edges and milling marks and just generally settle into their place until they're relatively smooth. I would tend to think the first oil change will be one of the worst, but I could be wrong.

From my generally reading of replies, I'm thinking it's gunna be either Idemitsu or Amsoil SS. Re @FowVay do you really think the slightly thicker Amsoil ATL is significant? Amsoil has a significantly lower pour point, so it seems like the extra viscosity won't be a problem in the cold(???). Amsoil KV @ 40 = 30.8, Toyota WS = 23.1....Amsoil KV @ 100 = 6.3, Toyota WS = 5.3. I'd be curious to see the curve on these. It looks like the Amsoil is more similar to WS at higher temps, starts thickening up at mid-temps (40C), yet retains fluidity at super low temps (WAY lower pour point than WS)....yet it somehow ends up with a lower VI? I'm still not sure how that works. Seems like if it's similar at high temps, but remains fluid much lower, the VI should be higher (???) than one that's similar in high temps, but doesn't go as low? I'm still confused on this.

Anyway, thanks everyone for all the input and great info!
 
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Yup, I’ll drive it, service it as recommended, sell it, life goes on.

Just more BITOG neuroticism centered on the belief that one can know the unknowable - namely by looking at ATF you can determine it’s “crap” at 21k miles.
Why is my new ATF almost as clean as new with towing weight at maximum to the Rav4at more then 40,000 miles. Could it be because it is a premium oil to handle the job without any question, and at the same cost? Group 2+ vs a Group 5. But then there are those "people" on BITOG that want to seem more virtuous then others on how they buy the cheapest and lowest grade "price point oil" and squeak by with good #s. Duh, I know dark oil doesn't mean bad oil, but I do know when the "crap price point WS" was dumped I got sick from the smell in a 24 x48 insulate garage and had to open up the door in a -10 below night till I could get rid of the burn't up crap WS oil. The WS could not handle the job and was so far degraded. Boy that WS is "so grand" it won the "so burn't I am going to vomit award that I need a respirator just to finish an oil change award." Go ahead use your WS with pride. I will run a "non price point" oil, and pay the same, and far far far exceed WS in performance across the board.
 
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I got a ton of TLS-LV for $1/qt, or I'd still be using Maxlife or Castrol FS MV. Cheep and cheerful is the way I roll.

IMO transmissions that call for WS aren't picky, and Amsoil make some of the finest ATFs available.
 

ekolpack

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Why is my new ATF almost as clean as new with towing weight at maximum to the Rav4at more then 40,000 miles. Could it be because it is a premium oil to handle the job without any question, and at the same cost? Group 2+ vs a Group 5. But then there are those "people" on BITOG that want to seem more virtuous then others on how they buy the cheapest and lowest grade "price point oil" and squeak by with good #s. Duh, I know dark oil doesn't mean bad oil, but I do know when the "crap price point WS" was dumped I got sick from the smell in a 24 x48 insulate garage and had to open up the door in a -10 below night till I could get rid of the burn't up crap WS oil. The WS could not handle the job and was so far degraded. Boy that WS is "so grand" it won the "so burn't I am going to vomit award that I need a respirator just to finish an oil change award." Go ahead use your WS with pride. I will run a "non price point" oil, and pay the same, and far far far exceed WS in performance across the board.

I'm curious if you have any vehicles that have gone 2+ rounds with WS? Did the same issues remain after the first oil change (which might've been during the "break in" period?) If the oil was still trashed after a second round (ie. after break in), that would certainly be a bad sign for WS. I wonder if Toyotas came stock with Amsoil SS or Idemitsu right off the assembly line, would the first oil change would still look terrible just due to mechanical shear, etc?
 
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Daaaaamn, so many great replies here! Thanks fellas!

A few thoughts. Re @rob1715 "if WS is so bad, why do so many 'yotas last so long running WS?" This is a good point and definitely something I considered. I'm inclined to think it comes down to the mechanical design and implementation far more than a marginal improvement in the type of ATF (which is what I'm going for). Toyota seems to be amazing at building the best, most-reliable vehicles in the industry....that's their specialty and nobody is better at this. When it comes to oils/fluids, clearly they do an excellent job here too, but it's not their area of specialty....they're not the best of the best in the world when it comes to making oils. I believe that title goes to Amsoil. I think Toyota makes a cost/value calculation. They buy their oil (or at least the base) from a third party, who has to mark it up, and they need room left for their own markup to dealerships and then a massive markup to the end consumer. If they used super high-end oil with tons of $ in R&D as their base (such as Amsoil), there'd be no margin left. So they make a typical engineering efficiency calculation like all car manufacturers make for every part in every step of the design process that the component in question (in this case, WS oil) is good enough, maybe even very good, while being cheap enough, maybe even very cheap. That's what it seems like to me anyway, as a random internet person with absolutely no understanding of the actual way Toyota Corp works or what criteria they use to make their cost/value calculations ;)

Basically, is Toyota WS good, maybe even very good? Good enough to keep many already very, very well built, well-engineered vehicles going for many thousands of miles? Yes. Are many of these vehicles *cough*Hilux*cough* so good that they could probably run on Canola oil? Yes. Could WS be better? Yeah, I think it probably could? Have there been examples of Toyotas surviving EXTREME torture tests, such as running them with no oil, or on original oil after 100k miles or other such ridiculous things? Yes. So I think that makes the case that why Toyotas last so long is mostly due to mechanical variables, not so much outstanding OEM oils. I think there's room for marginal (not huge) improvement there.

Amsoil is to oil design and manufacture what Toyota is to vehicle design and manufacture. I'm just trying to get the best of both worlds.

Re @Mainia I've heard this kind of thing from several folks in online forums or on reviews (ie. that original OEM fluid or some cheaper fluid was trashed, new Amsoil or other such fluid looked brand new at the next change after 30-50k miles). I notice this is often on newer vehicles after the first fluid change. I'm no transmissions specialist, but could it be that new transmissions have to be worn in? I know this is the case with difs and transfer cases. The fresh gears have to shear off a bit of fresh sharp edges and milling marks and just generally settle into their place until they're relatively smooth. I would tend to think the first oil change will be one of the worst, but I could be wrong.

From my generally reading of replies, I'm thinking it's gunna be either Idemitsu or Amsoil SS. Re @FowVay do you really think the slightly thicker Amsoil ATL is significant? Amsoil has a significantly lower pour point, so it seems like the extra viscosity won't be a problem in the cold(???). Amsoil KV @ 40 = 30.8, Toyota WS = 23.1....Amsoil KV @ 100 = 6.3, Toyota WS = 5.3. I'd be curious to see the curve on these. It looks like the Amsoil is more similar to WS at higher temps, starts thickening up at mid-temps (40C), yet retains fluidity at super low temps (WAY lower pour point than WS)....yet it somehow ends up with a lower VI? I'm still not sure how that works. Seems like if it's similar at high temps, but remains fluid much lower, the VI should be higher (???) than one that's similar in high temps, but doesn't go as low? I'm still confused on this.

Anyway, thanks everyone for all the input and great info!
Yes, good point and we see this with all rear diffIs in FWD bias AWD with 1/2 qt oil. But there were people still having burnt issues on their second dump with WS. We see 100,000 UOA where WS failed with very high #s. Sorry a semi-synthetic ATF is just not a winner in todays day and age. Why bother with it when you can make a group 3 for the same cost (Toyota's cost).
 
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Yep, semi-synthetic garbage. You can run it, so I don't have to. You can run black ATF in your car, I chose not to. At 21,000 and black in my book, that means garbage sub-standard oil. Yes, DRAMA!!!! But then again if you have an external oil cooler you can limp WS to a longer time frame till it turns black on you...go ahead.
Remember, black is the absence of color. From a scientific perspective. Although; all of us describe it as a color. IDK? We type in black....
 
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I'm curious if you have any vehicles that have gone 2+ rounds with WS? Did the same issues remain after the first oil change (which might've been during the "break in" period?) If the oil was still trashed after a second round (ie. after break in), that would certainly be a bad sign for WS. I wonder if Toyotas came stock with Amsoil SS or Idemitsu right off the assembly line, would the first oil change would still look terrible just due to mechanical shear, etc?
I dumped my daughters Mazda 3 ATF at 100,000 miles and it was never replaces as it is a one owner who used the dealership exclusively and I have all the records. I replaced it with Ravenol, and it still appeared in pretty good shape, far far better then the Rav4's crap WS. Wasn't burn't like the WS.
 
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Yes, good point and we see this with all rear diffIs in FWD bias AWD with 1/2 qt oil. But there were people still having burnt issues on their second dump with WS. We see 100,000 UOA where WS failed with very high #s. Sorry a semi-synthetic ATF is just not a winner in todays day and age. Why bother with it when you can make a group 3 for the same cost (Toyota's cost).
Every subsequent fill of WS has remained clean, IME.

Even some factory fills remain clean. This picture is from the original WS on a 2016 Prius with over 100K:
EACF2DB2-B444-408C-BA06-A492102A55BC.jpeg
 
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Remember, black is the absence of color. From a scientific perspective. Although; all of us describe it as a color. IDK? We type in black....
Tell be about the the horrid burnt smell that a normal person could not stand. I owned a hobby Audi repair shop and did many trans oil changes and did many other brands through word of mouth. I never smelled more burnt oil then I did with my wife's Rav4 I did see some black ones, but that was at 100,000 plus miles. The WS just plain degrades from heat. That burn't almost an acid effect to your senses "to me" stating it is a degraded spent ATF. Sulfur additive degraded to the point of break down?You tell me?
 
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I think people are making a little bit too big of a deal the dark color that WS turns into. The initial drain is dark, that’s about it. Whether that’s at 20,000 miles or 100,000 miles, it’s dark, but the subsequent drains are not. I’ve never had a transmission issue with the WS. And quite honestly, I know of no one who’s had a transmission issue with their Toyota car or truck, using WS fluid.
 
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Why is my new ATF almost as clean as new with towing weight at maximum to the Rav4at more then 40,000 miles. Could it be because it is a premium oil to handle the job without any question, and at the same cost? Group 2+ vs a Group 5.

Could it be? Absolutely! Can you say it is based on the information you've provided? NOPE!

I really don't give a **** about WS and I don't care what you decide to use but you can not look at dark ATF and come to the conclusion you came to. Well, not logically or credibly. You have no leg to stand on declaring it "crap" based on what you've provided. Just more BITOG hyperbole!
 
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Could it be? Absolutely! Can you say it is based on the information you've provided? NOPE!

I really don't give a **** about WS and I don't care what you decide to use but you can not look at dark ATF and come to the conclusion you came to. Well, not logically or credibly. You have no leg to stand on declaring it "crap" based on what you've provided.
So ATF smelling like 50 1 week old corpses sheep in my garage, that I had to open my door and wear a respirator to finish the job tells you nothing. Of course not. Just like I will not run a group 3 in my turbo car with it's glowing red turbo. I buy the oil that guarantees to fit the job with worse case scenario that could get into and I did, and I do. Why buy WS when there is so far far better oil for the same cost. And millions of milles run safely with now issues with aftermarket quality oil. Nothing like group 2+ ATF, huh? I guess I am with the "many others" who left WS stellar performance for something even better.
 

Astro14

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So ATF smelling like 50 1 week old corpses sheep in my garage, that I had to open my door and wear a respirator to finish the job tells you nothing. Of course not. Just like I will not run a group 3 in my turbo car with it's glowing red turbo. I buy the oil that guarantees to fit the job with worse case scenario that could get into and I did, and I do. Why buy WS when there is so far far better oil for the same cost. And millions of milles run safely with now issues with aftermarket quality oil. Nothing like group 2+ ATF, huh? I guess I am with the "many others" who left WS stellar performance for something even better.
So, you’re not basing your assessment on color, but on smell?

Smell is the definitive analysis needed to condemn an oil?
 
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So ATF smelling like 50 1 week old corpses sheep in my garage, that I had to open my door and wear a respirator to finish the job tells you nothing. Of course not. Just like I will not run a group 3 in my turbo car with it's glowing red turbo. I buy the oil that guarantees to fit the job with worse case scenario that could get into and I did, and I do. Why buy WS when there is so far far better oil for the same cost. And millions of milles run safely with now issues with aftermarket quality oil. Nothing like group 2+ ATF, huh? I guess I am with the "many others" who left WS stellar performance for something even better.
Again, I don't know if you're being intentionally obtuse because you clearly have an agenda but I'm not advocating for anyone to buy WS over anything else. All I'm saying is you can't categorically declare WS "crap" because it came out dark and with an odor. That's all. That's it. It's America brother, buy whatever you want, but know the limitations of looking at and smelling ATF and making wild speculative accusations about the quality of an ATF that is almost universally used in vehicles that are well known for their longevity.
 
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Same. And most people do not change it until 60-100K, if at all.
WS fluid is probably the most criticized fluid I’ve ever seen (outside of Dexcool), but at least Dexcool had failures early in their application. WS didn’t.

It’s mostly because it’s not synthetic and people automatically assume it’s inferior. The other thing is fluid color, it changes color pretty quickly as factory fills and that scares people. It scared me the first time too...74,000 miles. Fluid looked almost black in my Lexus LS460...shifting fine, changed it, still shifted fine. Preventive maintenance. Every change thereafter came out cherry red. Never an issue up till 180,000 miles when I traded it in. Now I have a 2016 Avalon...fluid was dark at 50,000 miles, but no shifting issues. Now at 86,000 miles, shifts like a dream.

I’m sure other fluids are good, but there’s nothing wrong with WS fluid.
 
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