2021 MX13 pac car dpf and scr efficiency issues in need of egr tuneup

[mikkhh]

From an engine standpoint yes without a doubt the EGR cooler flow is important for it running right. It seems to me that if EGR delta P sees lower than expected pressure coming from EGR side then engine ecu will try to compensate by raising exhaust back pressure. That would make logical sense for me. Also I think that the soot on cooler is going lower cooling efficiency and that makes for hotter intake gas and that makes more need for boost since hot air is not as dense as cooler air. So in theory the fuel mileage is going down and engine wear is going up. Also NOx gases are going UP since the combustion temperature is increased and therefore there will be lots of NOx faults due to this EGR cooler not being as efficient...

Since there are two same year make model same usage tipper trucks I would get good before after reference comparision to see if there is fuel mileage benefits. That way there would be an incentive to keep these systems working properly by doing preventative maintenance. These trucks are not going further than 100 mile radius from workshop so on this case there is no big towing hurdles to be afraid of and towing equipment is there is there would be need. First truck is at work now, if there is visible gains then it will get serviced soon, if not then at the next oil change. The thing I am trying to find out here here is to show that EGR tuneup is not only for prevention of issues but it can also help fuel mileage wise.

If and how much fuel consumption gets better is the main question. When there is visible difference that outweighs the cleaning cost benefit for a fleet then those will get cleaned like every two years along with baking the cans and yearly sensor clean and check.

Most big fleets keep trucks for up to 3years OR 250 000 miles whichever comes first and then replace with new ones. Since they are the majority of new truck buyers the dealer does want to show minimal running costs - 90 000 mile oil changes, no EGR tuneups. Most likely there are no big failures within first three years. I think that is why there is minimal talk about PROPERLY maintainig those expensive vehicles. If there would be talks about need for oil changes at 10 000 miles (due to soot load in oil due to EGR and fuel in oil due to DPF regens) and yearly or over year emissions tuneups then there would be way less incentive to buy new trucks.