I see Toyota/Lexus use Toyota Type IV transmission fluid in most of their automatic transmissions. I had the fluid in my RX300 changed to Mobil 1 full synthetic about 30,000 miles ago (they did a good flush with 14 quarts of synthetic, total) and it's ready to be changed again. Should I stick with the synthetic or go back to the Toyota Type IV? Mobil 1 is listed as an alternative to Toyota Type III and IV on the Mobile 1 website.

Got 120,000 on the odo - no sign of transmission problems yet!

 

I wouldn't go back to Type IV. I plan on sticking to Amsoil ATF myself.

 

I`d stay with the Mobil-1 synthetic.your better off with that than the Toyota fluid.The Toyota fluid just doesn`t impress me at all.

 

Most people on here are very happy with Amsoil ATF & Mobil-1 Synthetic ATF.

I changed to Amsoil and was very happy with it. I then changed to Royal Purple ATF due to how impressed I was with their gear oil in the rear end and transfer case.

Either way, you can't go wrong.

 

I remember a few were also using Redline here.

 

Intersting. I thought there would be much more of a split than this - with more people favoring going back to OEM-specified Type IV.

Maybe I'm getting paranoid about all these transmission failures..................

 

I'll set up a poll in another thread.

 

New forumula Mobil 1 syn ATF here...just starting to put miles on it. So far it seems to run perfect. I'm gonna do a drain/fill this friday to change out 75% of my fluid with synthetic. I'll make a post this weekend and keep everyone posted as to how the new formula is holding up.

 

I have over 10K on the new forumla Mobil 1 (100% fluid replacement) and it is performing perfectly. But then again so did Toyota Type T-IV for the first 130K. I will monitor its condition closely. The current plan is to do a d&f every 30K including dropping the pan and changing my felt filter.