Today I went to get my transmission fluid drained (mechanic advised against a flush), my car has nearly 30k on it and as far as I know, the ATF has not been changed ever.

I asked for Amsoil Synthetic ATF, after waiting a hour or so, the delivery finally came. However, when I looked at the bottle, it was Castrol Syntec Dextron III/Mercon instead of the Amsoil. Figuring it was already there, I just took it. Now my question is, how much of a difference is Castrol Syntec vs Amsoil?

How long will Castrol Syntec last before needing a change?

Also, is it a good idea to drain the tranny fluid again and fill it up with Amsoil? (There should be some regular factory ATF mixed in there too)

Thanks

- hito

 

I have 65k, just changed to MOBIL 1 (syn). It feels REALLY nice, smoothe, though when u floor it to downshift or whatever, in situations necessary. I could feel the car chirp and shift a lot quicker, though that feeling doesn't seem like its good.

TOday it chirped a bit or clunked, something just didn't feel right. I am thinking of selling my ATF SYN and just go MOBIL ATF (reg). I only changed/drain/refilled 2 quarts of mobil 1.

 

Hito,

Next time you need AMSOIL, let me know...see my post in the Group Deals section. Since you did a drain and refill, you obviously have a mixture of the castrol product and the petroleum fluid that came in the car. While this will work, it is not optimum...it will take several changes, using the drain/refill procedure to raise the concentration of synthetics in the system.

I have not used Castrol synthetic ATF nor do i know anyone who has. I have used AMSOIL ATF in every vehicle I have owned since 1988...I have some customers using this fluid in their Nissans and some are approaching 200K with absolutely no transmission problems and a commercial account with a County maintenance dept who uses AMSOIL ATF in ~120 Sherriff patrol cars. I installed AMSOIL ATF in my '98 max when it was new and I sell a lot of it to our members. AMSOIL ATF is fully compatible with other manufacturer's fluids, synthetic and petroleum based, and it is recommended for use up to three times longer than conventional fluids.

 

And the AMSOIL is good for 60,000 until a change is needed, according to them. I use it in all our Nissans.

 

I agree with Talkinghorse...go with the Amsoil. I run it in my Max - 1999 GLE with 173,xxx - as well as my wife's Tahoe. While you are at it put some Amsoil in the engine.