So, I just changed my transfer case and diff fluid in my CX-7 to Mobil 1 synthetic. I want to change my transmission (6sp auto) fluid to synthetic too. It uses 3309 which Mobil 1 Syn ATF is not compatible with.

The synthetic ATF brands that I've found that meets the 3309 specs are Amsoil, Redline, and Royal Purple.

I know Royal Purple is good but it's too expensive. Redline seems to be iffy (hit or miss) on some reviews. From what I've read, Amsoil seems to be better than Mobil 1.

Anyone got any experience with Amsoil?

I`m Batman wrote:So, I just changed my transfer case and diff fluid in my CX-7 to Mobil 1 synthetic. I want to change my transmission (6sp auto) fluid to synthetic too. It uses 3309 which Mobil 1 Syn ATF is not compatible with.

The synthetic ATF brands that I've found that meets the 3309 specs are Amsoil, Redline, and Royal Purple.

I know Royal Purple is good but it's too expensive. Redline seems to be iffy (hit or miss) on some reviews. From what I've read, Amsoil seems to be better than Mobil 1.

Anyone got any experience with Amsoil?

I put Mobil 1 in my Volvo a year or 2 ago. I found it interesting that it originally met 3309 specs, and then it didn't. Must've reformulated. I've used Redline in my RX8, but that was manual. It was good stuff (better than the Royal Purple that was previously in the RX8, IMO). No Amsoil experience, though.

I've never used Amsoil ATF, but their oil is great. It exceeds most testing, and most people I talk to love it. Only issue I have with Amsoil is availability. For ATF, it's not a big deal because you shouldn't be topping it off, but for oil, it sucks, since you can't go get it at the local parts store generally.

Cool! Amsoil it is then! It's over $100 just for the ATF. I've already replace the MS3 MTF with the Motul synthetic stuff. The only thing left that's not synthetic is the CX-7 ATF. I just want my car(s) to last as long as possible.

Huzer wrote:I put Mobil 1 in my Volvo a year or 2 ago. I found it interesting that it originally met 3309 specs, and then it didn't. Must've reformulated...

Yea I saw that when I was doing my research. I even contacted Mobil and asked them the same question. They said that it doesn't meet the 3309 specs and it might harm the tranny.