I have really been liking my '14 Promaster I bought in Sept. And as an old mechanic, I have come to appreciate the benefits of synthetic lubes in vehicles. I've already bought Shell's Synthetic oil for the motor as my first 5k mile service is coming up shortly. Is it worth it to take care of the auto transmission the same way and drop the pan to wipe it out well and change it over to synthetic ATF? I retired as a Navy Nuc plant mechanic last century. I'm a big believer in preventive maintenance.