Looks like we have a good feedback for z1 alternative. z1 is getting expensive and its fluid has a short life. Once I ran out of z1, I will go for Mobil 1 synthetic ATF. I used it before on toyota and it is good stuff. New Formula mobil 1 synthetic atf said on the label is z1 compatible.

https://acurazine.com/forums/3g-tl-2004-2008-93/mobil-1-synthetic-atf-712153/

 

I'd stick with OEM fluid.

 

nothing but good experiences from z1 so im going to stick with it

 

I could be wrong, but from my experience with z1, drain and refill every 15-20k, the old fluid appeared to lose its viscosity compare to the new fresh z1. That is why the old fluid creates more of grinding noise, jerking, harsh shifting compare to the new fresh z1 fluid. One thing I know for sure, z1 fluid does not last long in 2nd gen. It lasts 30k most at a normal operating temperature.

 

really ? i drain and fill every 60k on a 1g

 

I am not sure about 1g. But, even 99TL has different aft cooler system then 00+. To me, Acura tried to correct the morning shifting issue in compromising of a minimal cooling for the aft fluid. If you are aware, high temperature substantially reduced the fluid life, yielding minimal protection to the transmission in general, besides the second and third gear issue.

 

well maybe ill give mobil1 atf a try next time, since my tranny is currently slipping

 

Seems like the Z1 doesn't last as long for me either. Maybe because i only did a 3x1.

 

From what I read, the main reason that you cannot use a substitute in place of z1 is because z1 fluid is thinner than most of atf fluid out there. Dexron III is okay to use as a short term, it is not because Dexron III lack of additives, it is because dexron iii is a thicker fluid and honda has problem with fluid flowing passage. With the new Mobil 1 synthetic atf (New Formula), fluid is thin enough to use in place of z1 with better protection, and of course will remain longer protection under high temperature condition.

I believe Mobil 1 Brand is trustworthy once they have it on the shelf and what it is listed for.

Comparing the old z1 with the new z1, it seems like the old z1 has no slicky feel in it. so, obviously it wont shift as smooth as the new z1. I still have a case of z1 if someone wants to trade for mobil1 atf syn new formula.

 

Take a look at the ATF Viscosity Comparison chart. That is why amsoil can be used in place of z1.

ATF Viscosity (cP) Comparisons

MERCON <20,000
MERCON V <13,000
Mercon SP <9,500
DEXRON III <20,000
DEXRON VI <15,000
Chrysler ATF+4 <10,000
AMSOIL ATF 9,326

 

Amsoil rocks. For me, it created firmer, more decisive shifting. Going from 2nd to 3rd, in particular, it feels like my front end is reaching out and taking a bite out of anything in front of it.

 

From my understanding is that none of them met the antifoaming requirements for our trans. Of all the fluids out there i think the ONLY one i would try would be Amsoil

 

I'm not sure how much more expensive Z1 costs compare with Mobil 1? But you can get the exactly same fluid cheaper from Honda dealer (with Honda label instead of Acura).

 

So would you go with Amsoil over Z1?

 

Probably not.

 

Back in the spring, my 5AT was shuddering something bad, so I invested in a case of ZF1 and did the 3*3+3. This, after I have religiously performed the 3-quart drain/refill every 10k since I bought the car (used w/83k). Fixed the shuddering, but for ONLY about 6,000 miles. Then it came back, as bad or worse than before I did the 3*3+3.

Frustrated and concerned, I felt had two options: Transmission shop, or a different fluid for a hail-Mary. I opted for the Mobil1 Synthetic ATF. Vaccuumed out 1 quart ZF1 and replaced with M1. Immediate difference. Couple days later did the same thing, even better. Few thousand miles later, drained and refill, 2xM1, 1xZF1 (had some ZF1 left over sitting on the shelf). Been running this way for better than 10k miles and I love it. No shudder; quick, firm shifts. Can't wait for another 4k miles, I get to do another drain/refill and add more M1!

My two cents, I recommend it.