Switching from trip miles to odometer
 

So I decided to start tracking maintenance in Fuelly/Gas Cubby and realized I have to track fillups by odometer instead of trip miles. I know how to change the setting, but my question is how to make the switch without losing data from the last fill up. If I just add the most recent fillup in odometer, it uses 0 as the previous odo reading and therefore no mpg is calculated. If I change the previous fillup's odo to what it was at the time, it loses that fillup's mpg. What's the right way to do this?

The best way to make the switch is to create a "new" vehicle for the change. Otherwise, the trip distance will be read as the odometer reading on the old entries and cause most of the records to have syncing errors.

Ugh, not really what I wanted to hear or want to do. But I might. Follow up (asked this elsewhere but got no reply): does the iPhone app have notifications? I see the reminders but they're not triggering a notification that service is about to come due or is already overdue. If not that's a dealbreaker...I'd like to switch from another app I'm currently using to Gas Cubby, but if notifications don't exist I can't do that.
Thanks in advance.

Yes, there are notifications that should appear in the iPhone's notification screen. Please go to the iPhone's Settings and make sure that notifications for Gas Cubby are enabled.

Notifications for Gas Cubby are on - all except "sounds". I set up a reminder to have me check the oil in one of my cars as a test, starting Oct 1, but nothing is happening.
Suggestions?

Verify that your data has synced, then delete and reinstall Gas Cubby. Make sure to enable notifications when opening the first time. Login by tapping "Set Up Sync".

No good. Notifications are enabled but nothing's popping up on the iPhone. I do see the reminder and it also shows on the PC.