viscosity of various ATFs?

[LScowboy]

Quote:
it seems to matter less what viscosity an ATF starts out with and matter more how well said viscosity holds up.


I understand, however the huge viscosity shift from Toyota T-IV to Toyota WS still makes me a bit nervous to switch fluids in my Aisin A340E

 

[dnewton3]

Originally Posted By: LScowboy
... yes, I could research this for half a day and probably come up with the answers, however it is much more efficient if a BiTOG ATF expert answers my question in 30 seconds off the top of their head ...


Yes - it is easier when someone else does the work for you ...

When you get solid technical answers, and eschew them for market hype, it taunts those who went to the effort to help you in the first place. You got two good answers (one of vis and one of grade designation monikers), but you wanted both of them "dumbed down" to the lowest common denominator. That kind of info is easy found by searching any lube maker website.

I was already aware of you previous member ID status; I realize you've been here a long time. But that just makes your recent tom-foolery that much more in question. You're not a newbie here; you should realize how things work here.

Like it or not, it's my job as a MOD to weed out the trolls. If you are not one, then I offer this sincere public apology; I am sorry for offending you.

BTW - AFAIK, Bob is still with us; it is Tony, our dear departed friend and leader, who passed. If I am mistaken here, someone please correct me.

 

[LScowboy]

Quote:
When you get solid technical answers, and eschew them for market hype, it taunts those who went to the effort to help you in the first place.


no one was taunting anyone, my neighbor simply asked me what SAE grades would the various factory fill ATF's equate to? - he is kind of a shadetree mechanic, I was a little embarrassed that I didn't know off the top of my head, so I simply asked here, where people know these things by heart

everyone else here except you seemed to think it was an interesting question, I even got a cool chart I hadn't seen before

why turn a nice innocent question into something negative or hateful?

(edit- mod), you don't seem happy these days

 

[babyivan]

Originally Posted By: LScowboy

I understand, however the huge viscosity shift from Toyota T-IV to Toyota WS still makes me a bit nervous to switch fluids in my Aisin A340E


I'm in total agreement with you. I won't use Dex VI in my Ciera even though it claims to be backwards compatible.
I just did a filter change and used Castrol Dex/Merc for my '87 car that's originally spec'd for Dex II.

Not that I don't trust the info on the different characteristics of the available fluids out there, I'm just a very cautious person and making two spec'd fluid jumps (Dex III & Dex VI) makes me uncomfortable!

 

[dnewton3]

DEX VI is backwards compatible in most every application for DEX III, but there are a few notable exceptions; one being the Allison 1000/2000 series prior to 2007. That is because of a chemistry compatibility issue with regard to the seals Allison used, not the vis itself.

The topic of Vis, in regard to DEX VI and DEX III is greatly misunderstood. DEX VI has twice the vis retention (and also 2x oxidation resistance) than the former fluid. While DEX III will start at 7.x+, it will quickly drop into the low 6.x range, and even down into the mid 5.x range. DEX VI, OTOH, will retain it's vis far longer. So if your ONLY concern is about vis, then you're in the wrong position, as DEX VI will actually fare better over the long term. And again, it will also resist oxdiation much better as well. Only if you know of chemistry issues (and there are only a few that I'm aware of), should you have concern.

And BTW - if a lower starting vis is what you fear, then by gosh don't touch that bottle of MaxLife; it also starts with low vis (6.1?)! And yet people swear by it, while they curse the DEX VI. Just goes to show how bigoted and uninformed some folks are. I'm not saying they are completely interchangeable; I'm just pointing out how single-minded and one-sided some folks tend to be when thinking about their favorite (or despised) lube.

 

[Jeff_in_VABch]

LS Cowboy:

Like one of the posters replied, most ATF appears to be in the 20W range.

If we knew what aspect of transmission operation you are interested in, we could likely direct the discussion to that aspect. I only have direct experience in choosing a fluid for performance applications. However, driveability and durability are definately different topics.

In a performance transmission, you definately want the fluid thin as possible.