It should be telling you when the 24 hour regens are triggered, the C&C’s indicate like the pickups (verified on a friends 2022 5500). If you’re in park the regen message goes away. Have you monitored it around the 24 hour mark for a plus/minus a couple hours to see. You can divide your total hours by 24 and that should put you in the ballpark. 24.3 hours is about the mean time per regen for me, on 24 hour regens.
Interesting on the mileage, mine hardly changes in regen unless the roads are wet. The evaporative cooling on the DPF really takes a lot more fuel to regen.
Mine's the exact opposite. I agree it should be telling me when the 24 hour regen is triggered but it doesn't. And when it's in park doing the stationary regen, it shows a message the entire time and does somewhat of a countdown during the last few minutes although I don't recall the specific details for sure. And I'm not going to do it again just to refresh my memory on the countdown details. Seems like it was the last 10 minutes or something like that.
And yes, I recently noted when a regen completed and wrote down the hours. The next day when the 24 hours was up I watched for the regen to start then checked the dpf screen. It never showed anything but the gauge with 0%. No message of any kind. This was just a couple weeks ago. I've watched that gauge many times during a regen and it never changes.
My instant mileage on the highway usually hangs around 18-20. When I was in regen recently it was mostly showing about 14mpg. Glad it only lasts a few minutes. Since my tanks hold 74 gallons, I can't really see it in my mileage over a tank run. I've been running around 12.5mpg mixed towing and empty. That's 8-9 towing and 19-ish empty.