Which 10W30 for Honda manual tranny?

[Audioquest]

There are a lot of debates raging in Honda forums about the pro/cons of using Honda brand MTF vs regular 10W30. In my case, my 91 CRX specs out 10W30 or 10W40 motor oil right in the manual (obviously before Honda had developed their own MTF). I'm currently running the MTF and it don't notice any difference from 10W30. But, I'm due for a change and I'm thinking of switching back to motor oil (many say the MTF is too thin). The problem I see is that back in 1991, motor oil was SG grade and was a lot different than today's SN grade.

So, should I stick with the "thinnner" Honda MTF, or go back to 10W30? If so, which brand motor oil would you recommend running?

 

[BrianWC]

If this tranny has been run on motor oil most of its life I wouldn't stress MTF if you aren't having problems. But I would point out, my old SAAB 900 spec'd 10W30 and I got much smoother shifts when I switched to a 5W20. Every situation is different, though... MT fluid/oil has a lot less stress placed on it than motor oil. I'll let a true expert chime in on that, though...

 

[addyguy]

I'be read on here that Amsoil's MTF (a 5W-30?) works really well.

 

[bepperb]

There's not a lot of difference between the Honda MTF and a PCMO, the VOA's I've seen have it with a ton of calcium but no other additive and it is a bit thinner (the post 2006 version). In Ontario I might stick with the Honda MTF just for easier shifting in winter. But if you don't notice a difference then from a longevity standpoint there really isn't going to be a difference between Honda MTF, AmsOil MTF and motor oil.

 

[Audioquest]

Originally Posted By: bepperb
There's not a lot of difference between the Honda MTF and a PCMO, the VOA's I've seen have it with a ton of calcium but no other additive and it is a bit thinner (the post 2006 version). In Ontario I might stick with the Honda MTF just for easier shifting in winter. But if you don't notice a difference then from a longevity standpoint there really isn't going to be a difference between Honda MTF, AmsOil MTF and motor oil.


The vehicle is stored in the winter, so low temperature shifting isn't an issue. I have heard that PC produces Honda's motor oils, but I thought the MTF was made by Idemitsu? So, PC 10W30 would be a good choice, or another 10W30 with high calcium content?

 

[vinu_neuro]

https://bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2643850#Post2643850

 

[mechtech2]

I'd use a dedicated manual trans fluid.
Better shifting and wear.
But in a car that is over 20 years old, what are your expectations? Motor oil may be all it's worth.

 

[mva]

Originally Posted By: addyguy
I'be read on here that Amsoil's MTF (a 5W-30?) works really well.


+1

If you want the absolute best shifting use Amsoil MTF 5W30.