ATF: Amsoil Signature vs Toyota WS vs Idemitsu

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I'm planning a maintenance schedule for my 08 Toyota Land Cruiser (5.7 V8 w/ Aisin AB60 trans). I'll be using Amsoil engine, transfer, and crank case oil, but figured I should stick with Toyota WS for the tranny, as deviating from OEM ATF is sacrilegious in most auto circles. Long story short, I'm now second guessing that wisdom and considering a couple alternatives.

1) Amsoil Signature ATL. Main reasons are that Amsoil has a very long, well-established track record making great products in the US. There are tons of rave reviews about their fluid, with many claiming it improved shifting or noise or temps over OEM fluid. Also, it's fully synthetic vs. Toyota WS which is at best, a blend. Here are specs:

amsoil atf.png


2) Idemitsu type TLS-LV WS ATF. Although Amsoil says it is "compatible with" WS fluid, it's not specifically engineered to match the properties of WS fluid. Idemitsu TLS-LC on the other hand is specifically formulated for WS transmissions, but unlike Toyota WS it is full synthetic like Amsoil. It also has a slightly lower pour point and Brookfield viscosity (implying it may perform better in cold conditions), yet retains exact same kinematic viscosity at 40C (23) and 100C (5.3). You'd think this would mean it would have a slightly better viscosity index than WS, but for some reason it's a tiny bit lower (175 vs 177). Not sure what that's about. Can anyone clarify why this may be???

idemitsu atf.jpg
3) Toyota WS. I'd feel much better about this fluid if it were full synthetic. Maybe I'm off-base, but it's my understanding that although conventional oils have gotten much better over the years, the best conventional will not be as good as the best synthetic in most respects. It seems like this is just cost-cutting, profit maximizing measures by Toyota. Of course I could be wrong on this. That's why I'm here checking with the experts.

toyota ATF.png


Here's what I'm seeing, correct me if I'm off-base. The specs on the Toyota WS actually look very good, generally "better" than Amsoil, especially viscosity index, which is important. But I know specs don't often tell the full story, and these are pretty basic specs sheets at that. The Idemitsu is again, almost identical to properties of the WS, but it's synthetic and may be a little better in extreme cold. For this reason I'm tempted to go that route, but Idemitsu doesn't have anywhere near the track record and rave reviews of Amsoil. I've looked at other options like Mobil WS, Totachi WS, and Ravenol. Ravenol seems a lot like the idea behind Idemitsu, but I can't find published specs/data on it, so that's a red flag. MaxLife ATF looks like a competitor to Amsoil and it is actually certified for use in Toyota Aisin transmissions, but it just doesn't get the same level of rave reviews and people claiming it fixed existing issues. So I still think it's pretty much between OEM Toyota WS, Amsoil SS ATL, or Idemitsu's synthetic WS.

I should mention I'm not too worried about price. Land Cruisers are expensive vehicles that can easily go 500k+ miles, and I plan to keep mine a very long time. I don't mind spending an "extra" $20-$30/gallon on fluids to keep her in tip-top shape.

Also, I plan to change ATF every 50k miles. Does this seem reasonable for an Aisin AB60 trans with rare to occasional heavy use towing, off-roading, etc.?

I know there is an amazing amount of wisdom on this forum. I'd love your thoughts, suggestions, corrections, etc. Thanks fellas!
 
I mean, I don’t think using Amsoil would hurt anything, but I’ve been using WS fluid for a decade now in two different cars and it’s been good. First drain from the factory is very dark, and it scares you a bit, but after that initial drain the color remains pretty clean.

I’ve never had shifting or performance issues with it. I know it’s not synthetic, but like you said, the viscosity is very good, and as far as synthetic goes, there are people that actually prefer conventional in certain situations. Mostly rear ends/diffs, because they believe when heated the oil will not sling off the gearing as easily. Not sure how I feel about that...and not sure that has much of anything relevant to do with the topic either, but transmissions are different than engines. Maybe synthetic isn’t all that important for the application? I don’t know.

Either way, I guess try whatever you‘d like and if it shifts weird, just change the fluid back to WS. Most people in Toyota forums substitute Maxlifs for the WS with good results...I’ve never tried it, I just stick OE for transmissions because I’ve been burned before with a Honda.
 
Based on cost the Idemitsu product wins by a long shot. All three mentioned products (Ravenol, AMSoil, Idemitsu) are reputed to be very good oils but in this comparison the AMSoil is off-spec with a 18% higher viscosity as compared to the Toyota specification. The LV product is one full cSt heavier than the other two so that's a consideration. Whether it's a condemnation factor is up to you.

If I were spending my money at 50,000 mile intervals I'd be buying the Idemitsu product.
 
I am a anything but WS. After seeing almost black WS in my wife's 2014 Rav4 at 21,000 I could not get that crap out quick enough. It was a lease return from upstate NY and like new inside, and no soccer mom hauling as the back was like no one ever set foot in the back seats or hatch. I did a 100% flush and put in Redline D6 with 1.5 qts of Redline racing and 1.5 qts of Redline racing low viscosity to more match the D6 viscosity. I wanted to kill some of the slip agent as I like firm shifts. I added an external trans cooler as we tow with this car. The car has 60,000 miles on it now and is running great. I cracked open a trans line and had a paper towel below to see the color this summer and it is basically just a shade darker then when I put it in. Were the crap WS was almost black before. If I bought a new Toyota I would dump the WS at 10,000 miles and get the break-in debris out and put in Redline/Amsoil/high end oil or anything that would have some Gravitas other then crap WS. I do know WS holds up better IF you have an external oil cooler, that I think come on all Toyota trucks. This does not include the "oil heater" parts book name for the Toyota hockey puck oil heater, NOT oil cooler. If I owned a truck the crap WS would be dumped just the same. I see it as sub-stand garbage price point oil, and I want nothing to do with it.

And also a heads up with anyone with a AWD car/suv with the front wheel bias AWD, change your rear diff oil at 10,000 miles. That was jet black at 21,000 miles on my wife's Rav4 too. Get rid of the break-in oil. The rear diffs on all this type of car usally have just less of a 1/2 of a quart of oil. My Hyundai AWD I changed out at 2,000 (could not believe how dirty it was at 2,000miles) Then 7,500 still dirty and I think 15,000 and that started to stay cleaner but still dirty. I just dumped it at 28,000 and it was basicly clean. Now I can do the 30,000 mile changes as the rear diff is all broke in.
 
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I used the AMSOIL in my Tundra’s transmission about 40,000 miles ago. Shifts perfectly. Highly recommend it.

I believe your Cruiser is similar - drop the pan, change the filter. Reinstall the pan. Open a big fill plug on the side. Block open the thermostat with a cotter pin or finish nail, disconnect the fluid return line from the transmission cooler and place a catch bucket underneath.

Add 4 quarts, idle the engine. Fluid goes through the trans and cooler into the bucket. Refill and repeat. Three iterations will get clean fluid coming out of the return line. Plan on 12 quarts. Have a bit more on hand. Just in case.

Reinstall the return line and remove the thermostat bypass.

To set the level, have truck idling on perfectly level ground, have the transmission at the proper temp (Toyota Techstream works well here). Remove the standpipe plug, not drain plug, the other plug in the transmission pan.

Some fluid should dribble out. If so, you’re good, knowing that the pan fluid level is at the top of that standpipe.

If no fluid dribbles out, add 1/2 quart and recheck.

Reinstall the fill plug on the drivers side.

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.
 
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I think amsoil makes an incredibly robust fluid. I just serviced the 5r55 in my wife's aviator and the signiture series in it looked like the day I put it in there 80k+ miles earlier.

Personally, I think too much emphasis is placed on only using the factory fluids for at's.. I've used multi vehicle formulations for years across most manufacturer platforms with zero issues. In fact I just acquired a Lexus that calls for WS and I fully intend to use Amsoil signiture series in it too.
 
Oh the drama. Millions and millions and millions of vehicle miles using WS and you've condemned it as "crap" after 21000 miles.
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.
 
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I used the AMSOIL in my Tundra’s transmission about 40,000 miles ago. Shifts perfectly. Highly recommend it.

I believe your Cruiser is similar - drop the pan, change the filter. Reinstall the pan. Open a big fill plug on the side. Block open the thermostat with a cotter pin or finish nail, disconnect the fluid return line from the transmission cooler and place a catch bucket underneath.

Add 4 quarts, idle the engine. Fluid goes through the trans and cooler into the bucket. Refill and repeat. Three iterations will get clean fluid coming out of the return line. Plan on 12 quarts. Have a bit more on hand. Just in case.

Reinstall the return line and remove the thermostat bypass.

To set the level, have truck idling on perfectly level ground, have the transmission at the proper temp (Toyota Techstream works well here). Remove the standpipe plug, not drain plug, the other plug in the transmission pan.

Some fluid should dribble out. If so, you’re good, knowing that the pan fluid level is at the top of that standpipe.

If no fluid dribbles out, add 1/2 quart and recheck.

Reinstall the fill plug on the drivers side.

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.
In the Rav4 forums some new Rav4 owners where complaining about trans slipping in places like Canada and Minnesota during winter. Then went back to the dealers and they added more oil. One mechanic told a guy they get low levels right from the factory from time to time. I too had that issue following the level and temp change over to a tee. I then added another 3/4 qt and all has been fine since. I helped a buddy do his Toyota and we went to the set level and we/i added another 3/4 qt for good measure.
 
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I would NOT use Amsoil as it is not WS, but would use Toyota, Idemitsu, Ravenol and I'd add another Aisin ATF WS, the latter makes the trannies for Toyota. If you use a generic ATF of a good brand the problems do not appear quickly, but are transferred down the line and will appear once the miles begin to accumulate.
 
I would NOT use Amsoil as it is not WS, but would use Toyota, Idemitsu, Ravenol and I'd add another Aisin ATF WS, the latter makes the trannies for Toyota. If you use a generic ATF of a good brand the problems do not appear quickly, but are transferred down the line and will appear once the miles begin to accumulate.
What problems?

Amsoil ATL is not a completely generic ATF, it's been used for many years now, and tested rigorously in Toyota applications. Yes there are some very very slight delta viscosity @ given temperatures, but this has zero impact on the AT, and in fact if these tiny differences had an impact - such a tranny would be impractical for any road conditions.

Use the ATL with confidence.
 
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@ekolpack,

I changed my fluid in the 4Runner this fall, and used the Idemitsu ATF. Seems to work just fine; BUT, the shift points are a little different.
It almost seems thinner or more slippery. I'm going to leave it in until 100K and then re-evaluate things.
 
Land Cruisers are expensive vehicles that can easily go 500k+ miles
You're right. And here are some questions. Is the only way your Land Cruiser can go 500k+ miles is by using Amsoil? Or Maxlife? How is it that there are millions of Corollas and Camrys that have gone millions and millions of miles using Dex III, T-IV, or WS, without fail? I've asked those questions before and I have yet to have anyone directly answer them without doing some Cirque du Soleil and Whirling Dervish BS answer. Use WS and change it every 30 - 40k miles. Wipe the magnet, or get a Gold plug and be done with it.
 
You're right. And here are some questions. Is the only way your Land Cruiser can go 500k+ miles is by using Amsoil? Or Maxlife? How is it that there are millions of Corollas and Camrys that have gone millions and millions of miles using Dex III, T-IV, or WS, without fail? I've asked those questions before and I have yet to have anyone directly answer them without doing some Cirque du Soleil and Whirling Dervish BS answer. Use WS and change it every 30 - 40k miles. Wipe the magnet, or get a Gold plug and be done with it.
Corollas and Camrys are not really comparable to the OP's 'Cruiser. Light weight, FWD, typically easy use just isn't the same.

The decision, or analysis, must be more than just "fluid X is good" - it has to be a consideration of use pattern, component performance requirements and oil change interval.
 
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.
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.
 
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