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Castrol ATF

Question for you pros...
<br/> My mechanic who I trust wants to use a transmission fluid made by Castrol in my Accord that can supposedly be used in lieu of Honda Z-1 permanently.
<br/> The transmission fluid is full of Z-1 so my questions are:
<br/> 1. Is it ok to let him use this fluid in my vehicle?
<br/> 2. If the answer to #1 is yes, then will mixing this with Z-1 create issues? (He will just drain and refill the fluid, which of course does not remove all of the old fluid).
<br/> Thanks in advance.


  • edited June 2010
    **Correction to Line 4** The transmission is full of Z-1

    Why can't we edit our OPs?
  • edited June 2010
    Does the Castrol ATF say that it is compatible with Honda transmissions?

    I put Valvoline MaxLife ATF in my Honda.
  • edited June 2010
    I am no pro, but I own and drive Hondas. I would insist on the Honda brand fluid.

    What does your owner's manual say about this issue?
  • edited June 2010
    Honda doesn't refine and manufacture their own fluid. As long as the additives in the ATF meet the same requirements, I'd rather not pay Honda's inflated prices.

  • edited June 2010
    As much a believer as I am about oil brands being pretty interchangeable, I'd go with the Honda Z-1 here. Just too many cases of Honda ATs being troublesome.
  • edited June 2010
    I've gotten chastised a bit for this on other threads - but I don't trust the multi-spec fluids. They are engineered to meet lots of different specs so they will minimally meet them all - but are all of the specs really optimized? Well, they can't be optimized for your exact specs since some things are bent to accommodate other things. I've always thought of them as probably "good enough" but not "optimum." The exact spec will generally cost a bit more but to me it is cheap in comparison to messing with the health of the transmission.

    You will, of course, get varying opinions.

    FYI: with some internet searching you can find the exact Honda specs and then you can find them for any fluid on the market to compare.
  • edited June 2010
    I too am one that believes it's worth the extra few bucks to use only the exact tranny fluid specified in the owner's manual.

    Trannys are too expensive to risk. Tranny fluid performs functions beyond just a lubricant. It's a hydraulic fluid, a cooling fluid, and a seal preservative. It's also a major component of the torque converter, which is a fluid-transfer device that uses the fluid to transfer torque and to absorb energy when stopped. If it's not exactly correct you risk a very expensive problem.
  • edited June 2010
    First, I know Honda doesn't make the fluid. Second, I wouldn't take Castrol's word for it. Third, you can buy Honda OEM products online as cheaply as you can buy Castrol's product from a store, so you aren't saving any money. You don't have to pay inflated prices by buying OEM Honda products at the dealership.

    For all we know, Castrol might be the maker of Honda's Z-1 fluid. If that is the case, I still wouldn't assume the products are made to the same specifications.

    Knowing all this, why would you take the risk? What do you expect to gain? You won't save money and the Castrol product might not be as good as advertised.

    I will ask again, what does the owner's manual say? If the owner's manual lists the specifications the fluid must meet, and this product meets those specifications, go for it. If you are just going by Castrol's claims, good luck. Those claims might be a rare case of truth in advertising, but I wouldn't bet on it with nothing to gain.

    Jeffmw05, do an internet search for "Honda OEM parts." The last time I ordered OEM parts online, I got them for much less than I would have paid at the dealership.
  • edited June 2010
    Thanks for the input. I too am more comfortable with the Z-1. The dealer quoted me $67 to drain and fill the trans with OEM fluid and my mechanic wanted $50 or so. I think the $17 premium may be worth it. Thanks again.
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