Amsoil versus Honda Z1 viscosity question

[The Critic]

Originally Posted By: Lyondellic
Originally Posted By: Whitewolf
They are all about 5.9 to 6.0, very tight.


Relative to the spec, Honda Z1 is fairly viscous then. Amsoil was also heavy relative to the spec before the formula was changed last year. Some ATF's other brands, like RP Max ATF, are in the 7.4 range. This is also true for Redline D4 and Schaeffer's #204S-AT.

While the Z1 may start out at higher, the ending viscosity may be significantly lower than the Amsoil after the same amount of time.

 

[benjamming]

The ending viscosity on my 3 runs with Z1 ended up at 5.8, 6.0, and 5.6 for factory fill, 10,224, and 12,836 miles, respectively. Albeit, this is in the 4-speed auto from the 6th gen Accord.

 

[Lyondellic]

I just placed an order for 6 quarts of Amsoil Universal ATF. I had been leaning towards using ATD, but was influenced by the desire to run a fluid that was a closer match to the Honda Z1 fluid. It appears as though the Universal ATF is a closer match, so that's the route I opted to take. I also wanted to be able to rely on the Amsoil warranty, which would not have been possible if I used the ATD fluid. I will post my experience after performing a couple of drain/fills within the next 1-2 weeks. If all goes well, I will order 6 more quarts and perform two more drain/fills and call it a day.

 

[dorkiedoode]

awesome. looking forward to the results. hope it all goes well

 

[The Critic]

Originally Posted By: Lyondellic
I just placed an order for 6 quarts of Amsoil Universal ATF. I had been leaning towards using ATD, but was influenced by the desire to run a fluid that was a closer match to the Honda Z1 fluid. It appears as though the Universal ATF is a closer match, so that's the route I opted to take. I also wanted to be able to rely on the Amsoil warranty, which would not have been possible if I used the ATD fluid. I will post my experience after performing a couple of drain/fills within the next 1-2 weeks. If all goes well, I will order 6 more quarts and perform two more drain/fills and call it a day.

What went wrong with the Royal Purple?

 

[Lyondellic]

Originally Posted By: The Critic
Originally Posted By: Lyondellic
I just placed an order for 6 quarts of Amsoil Universal ATF. I had been leaning towards using ATD, but was influenced by the desire to run a fluid that was a closer match to the Honda Z1 fluid. It appears as though the Universal ATF is a closer match, so that's the route I opted to take. I also wanted to be able to rely on the Amsoil warranty, which would not have been possible if I used the ATD fluid. I will post my experience after performing a couple of drain/fills within the next 1-2 weeks. If all goes well, I will order 6 more quarts and perform two more drain/fills and call it a day.

What went wrong with the Royal Purple?


Royal Purple's Max ATF shifts very smoothly, but there are two things that I find irritating. First, the notchy downshift that is present when I come to a complete stop. This was not present with the Honda Z1 ATF, so I can only attribute it to the RP fluid. Second, I cannot fully explain it, but it feels as though the RP fluid is robbing horsepower. Acceleration seems to take more effort and the car doesn't feel as responsive. I was on the freeway the other day and found this to cause a lot of frustration when I suddenly found myself in stop & go traffic. The RP fluid did quiet down the whining noise my transmission was making, especially when using the reverse gear. My theory is that the RP ATF is more viscous than the Honda Z1 fluid, which may explain the items that I have described above. Honda transmissions are finicky, so I cannot say with certainty that the Amsoil ATF will be any better than the RP ATF, but there is no harm in trying both out. Who knows, when all is said and done I may end up with a 50/50 RP/Amsoil mix, or even back to 100% Z1 again.

Stay tuned...

 

[odessit]

I am very interested to see what happens. My Accord had annoying issue of rough automatic-downshifting to 3rd gear when going from 65 to 50 mph zone on a highway. I solved it by changing 3 quarts of Z1. I will do another 3 quart refresh in 2 weeks.

Just seems very strange that Z1 fluid with only 30K will behave badly.