It may sound stupid, but how can u tell when u regen. I have read where guys say how many times per wk they regen or clean filter lights on, but i have 8500 miles on my truck and am not aware of a regen yet. I can not notice a severe drop in fuel mileage, b/c I do not monitor it and can't hand calculate for other reasons. Won't have to worry after exhaust is on, but curious.

the smell.

yeah i smell mine when it regens. dont really notice engine tone or rpm increase. but mpg really drops

Mine gets a very noticeable moan/drone to the exhaust. I can feel it in the floorboard. At idle it is most noticeable. When I hear the note change, I always look to the right side mirror. I can see the heat trailer swirling around between me and the car next to me. The heat plume is massive.

I usually switch the DIC to the mileage readout and just watch it start dropping.

your idle rpm's should jump up a little as well; but the most noticable indicator is the smell. The rpm's jumping was how i always could tell.

if you can't stand next to it cause it's so hot then it is.

On mine the RPMs go from 700 to 800 or so. It seems to start once the truck has warmed up and hit over 30 MPH or so. It takes my truck mabey 20 Min to complete. Its nice to know because I was getting stuck in regen getting crappy mpgs because I was only driving 15 min or so to get to work and then shutting off the truck just before it was done.

I also notice it in the RPMs, and can smell it when I get out if the rig, smells like my E brake was on (no it wasn't!!), It was definitely hot back there. Although I've not seen the fuel econ on the DIC go down when I'm driving, the fuel needle seems to have moved more than what you would expect for the same trip. After a few regens you'll kind of put the small clues together and know when.

Yah i notice the smell the most...and since i put on my edge insight i just watch the soot mass and also the rpms at idle...they jump up about 100 or so