DEF re-gen cycle frequency
We've owned our 2012 Winnebago Tour for 2 years and traveled roughly 15000 miles. We purchased it with 17000 miles. I have yet to experience a DEF re-gen cycle. Isn't there a dashboard light to noti...
Forum Discussion
bullydogs1 wrote:
DEF has to be consumed all the time as it turns exhaust to water and a harmless gas...My regen light in my old coach used to go on about once every 5000 miles or so (once a year) and go off after about a half hour...Present coach has 10000 miles on it and it has not gone on once...Fuel mileage is better with the setup too..And although the door is on the right side..Im perfectly OK with adding the 2.5 gallon jug I buy and putting it in..not a big deal..The only coach I have ever seen with both the fuel door and the DEF port right next to each other is a Prevost...Even the driver side port for most coaches is on the rear of the coach...so you have to go back in and move the coach anyway.
jplante4 wrote:Mile High wrote:
So DEF is consumed if when not in Regen?
Yes. There's a typical EPA story here. They mandated a reduction in NOX which was met by recircing the exhaust gases like they did in cars in the 70s.
This in turn decreased the exhaust gas temps (EGT) and cause some unburned fuel to get passed through which caused diesel particulate matter (soot). The DPF removed the soot, but increased the NOX. Injecting DEF allowed the builders to cut down on the amount of recirc and increase the EGTs to reduce the soot and turning the NOX into water and N2,
The DPF and the SGR (where the DEF is injected into) are separate chambers that look like mufflers.
DEF is injected all the time. Regen increases the temp of the exhaust to "burn" off the soot in the DPF.
Confusing enough?
And thank you gentlemen for the thorough explanations. I had a misconception of how that worked!
