I am about 500 miles into the first cleaning phase using auto-RX. The car already seems quieter and I look forward to my commute every morning to check its progress. So far I am very pleased. Oddly enough the auto tranny is shifting smoother as well, but i nevert added any auto-rx to the tranny, only the engine. MY 1-2 shift is noticably less notchy and it downshifts more readily as well. What would cause this to happen? I'm stumped!

 

I've always wondered that with my old car. The tranny would shift different with synthetic or dino oil. I had an answer I finally felt made some sense but I forgot what it was.

 

I had the exact same thing happen in my 1993 Sable. I had the tranny replaced about 30k miles ago. I have replaced all the tranny fluid for 2 summers since then, it has always shifted really hard.

After about 500 miles into the cleaning phase of AutoRX...the tranny got smoother.

 

None of the above makes any sense as the AutoRX was not added to the transmission.

I have 100 miles to go in my AutoRX rinse phase and then will be switching to synthetic oil for the first time.

My engine seems to be quieter at idle and the car seems more responsive. However, I also had the throttle body cleaned during the rinse phase and that may also be a factor in the responsiveness.

My Maxima is a 5-speed.

The placebo effect is the cure for your automatic transmissions.