In a perfect world, soot from diesel fuel can be 100% burned. Unfortunately... we do not live in a perfect world.
Fact is only about 80% of fuel is burned during combustion.
Soot also contains fuel additives, oil additives, bypass from rings and seals, and other metal particles. These particles that are present in your diesel particulate filter cannot be completely burned during the regeneration process. The end result is ash that lays in your filter until it is physically cleaned.
So what's the big deal you ask? An 80% burn rate doesn't seem so bad you say.
Well, ash poses various problems over time for your DPF.
Ash acts as an insulator within the particulate filter. This insulator causes temperates to rise and creates backpressure.
Regeneration only cleans up to the next layer of ash, causing buildup over time.
Ash can only be removed by physical maintenance of the filter.
And even this information may not sound so bad, afterall I still don't need to clean my filter very often right...?
Well, the bad news is that many use a reactive approach to cleaning, only taking action when there is a problem. This reactive approach causes unnecessary delays and expenses.
Did you know that for every 2% a filter is contaminated, over 50% you lose 1% of fuel economy?
And did you know that the DPF warning light does not typically come on until the filter is 75-80% contaminated?
Well if you put a pencil to it, you'll see that fuel savings alone can more than cover the cost of scheduled cleaning.
Now 10% may not seem like much, unless you own a fleet of 50, 100 trucks or more.
As an example, let's say you truck averages 550 miles per day. And for this example it's on the road 20 days per month. Using an average diesel fuel cost of $1.945 per gallon, at 70% contamination you are spending an additional $339.60 in fuel...per month...per truck. And this all takes place prior to the filter light illuminating to let you know there's an issue.
So the next time you are reviewing annual vehicle inspections, take a hard look at filter maintenance. Getting ahead of the issue can not only reduce vehicle down time, but save you money each and every month.