I can get Castrol CVT fluid for a Fit for $24/gal vs $64/gal for the Honda's fluid. I find it hard to believe that there is really an difference.

Have any of you used non-Honda CVT fluid?

 

I do not know if there is a difference. However, there are numerous YouTube guys recommending to use the Honda fluid only.

I hope one of our Fitfreakers with a science background can offer some clarity.

 

"CVT fluid" doesn't have any enforced standards attached to it, so it can mean anything the manufacturer wants. I could slap a "CVT fluid" label on bottles of Dexron and sell it.
It's all about what the specific model of transmission needs to operate reliably. Honda says their fluid is the best. Castrol says theirs is just as good. As an owner, you could try sending in new and used samples of each fluid for lab analysis. Otherwise, it's just a question of brand-trust. How much do you trust each brand to do their engineering homework, and how does that correlate with cost?
Having tried Honda's MTF (which seemed to be 5w-something or thinner) in my '91 CRX, I can say that Honda doesn't always know best. Synchromesh (closer to 10w-ish) just shifts better.

 

Valvoline Synchromesh or Penzoil Synchromesh?

 

I plan to get enough Castrol CVT for two cars.

 

Yes? The half-used bottle on the shelf is Pennzoil.

 

I wouldn't use Syncromesh again in any of my cars. Its not good for softer metals either. It also doesn't hold up to cold weather well at all. I had to change my fluid within a year due to it failing and taking out my 3rd gear syncro in my VR4. Use the proper fluid and enjoy a happy transmission that will have predicable results.

 

Does your VR4 call for motor oil as MTF?
The L-series (Fit engines) manual transmissions are a direct evolution of the D-series transmissions they replaced, so I feel pretty confident making that recommendation. Honda literally just mirrored the 7th gen Civic transmission left to right (D-series engines are on the left of the engine bay, L-series are on the right) and made the typical gear ratio and generational tweaks. Honda MTF came into existence due to motor oil (which was previously the specified fluid) formulations had changed. Modern motor oil has a bunch of friction-reducing additives that make it too slippery for the synchros and drag rings to work as intended. In response, Honda started selling their original MTF formulation, which is essentially 1980s motor oil. They went with a thinner weight to improve fuel efficiency, and added a touch of gear oil additives judging from the smell.
Other auto manufacturers ran into the same problem, so they produced their own old-school-motor-oil formulations. Synchromesh is the GM-spec '80s-motor-oil fluid.

 

I've been down this road and also later tried motor oil as some people were "claiming" benefits. It didn't last well either. It has too many detergents and not the correct amount of wear inhibitors or proper friction modifiers. What it boiled down to was finding a proper high shock oil base that also met GL-4 requirements. My testing found that OEM Mitsubishi Diaqueen was the best formulation and second as Redline MT85. Even MTL or MT90 would have an influence on the shifting characteristics and they are identical in composition with very slight weight differences. My point being, don't try and play hero with transmission oils. Its a finite science and OEM's almost always have it figured out. They have countless hours of testing to back it up. What's an additional $20-30 a transmission oil change going to cost you if you have to rebuild your transmission just once in the lifetime of the OEM fluid transmission? Its so not worth it!

 

Those are all heavy gear oils. MT85 is 75w85 on the same measurement system as the 10w30 SF/SG that Honda recommended through the mid '90s.

 

I received the two gallons of Prestone Max coolant from Advance Auto yesterday - free overnight delivery. It was packed like they were shipping nuclear waste. 😂

 

Again weight is only one aspect of oils composition.

 

Anyone happy and satisfied with less expensive CVT fluid that is not the Honda brand? I want to have mine changed at 200K miles. No, it won't be the first time.

 

I personally would go with the Honda CVT fluid to be safe. Experimenting with such an expensive part isnt something most people like doing

 

I have done 2 CVT flushes and both times have used Amsoil CVT which in ny opinion is better than Honda fluid! I get no clunk of any kind when shifting from druve to reverse, etc. I will only use Amsoil because it is rated for extreme temps and we need all the help we can get here in the Tucson, AZ summer months especially! I don't believe that Honda fluid could handle the extreme heat. What do the Japanese know about extreme ambiant heat?