Short trips, city driving, and stop-and-go traffic are some of the biggest causes of DPF clogging and frequent diesel regeneration. If your truck is used for deliveries, local routes, or low-speed urban driving, the engine may never reach the temperatures needed to burn soot naturally — leading to active regens, parked regens, or even derate mode.
This guide explains exactly how stop-and-go driving affects regeneration, what symptoms to look for, and how to protect your DPF from excessive soot buildup.
Why Stop-and-Go Driving Causes Regeneration
DPF regeneration requires extremely hot exhaust temperatures (900–1,200°F). But during short-trip or low-speed driving:
- Exhaust temperatures stay low
- Soot builds up rapidly
- Passive regeneration never happens
As a result, the engine must rely on active or forced regeneration to clean the filter.
Driving Behaviors That Increase Soot Production
- Short trips under 10–15 minutes
- Constant stop-and-go traffic
- Low-speed delivery routes
- Excessive idling
- Cold starts in winter
All of these conditions prevent the DPF from reaching the temperature needed for passive regen.
Signs Stop-and-Go Driving Is Affecting Your Truck
- Regen happening every 40–120 miles
- Regen light comes on frequently
- Soot levels stay high even after regen
- Fan runs loudly more often
- Forced regens becoming more frequent
- Poor fuel economy
Risks of Repeated Regeneration in City Driving
- DPF clogging (rapid soot buildup)
- Derate mode (5 MPH limp mode)
- Excessive heat in the aftertreatment system
- Premature ash loading requiring cleaning
- Sensors failing earlier (NOx, temp, pressure)
These issues become worse the longer the truck stays in city-only operation.
How to Reduce Soot Buildup in Stop-and-Go Driving
- Take the truck on a 20–30 minute highway drive weekly
- Avoid unnecessary idling
- Use high-quality diesel and DEF
- Fix EGR, NOx, or temp sensor issues immediately
- Monitor soot and regeneration history using diagnostics
Tips for Delivery Trucks, Work Trucks & Local Route Vehicles
- Plan weekly “soot burn-off” highway runs
- Perform regen as soon as the dash requests it
- Keep engine and aftertreatment system at proper operating temperature
- Use a diagnostic laptop to check soot levels before work shifts
When Stop-and-Go Driving Leads to DPF Failure
If regen becomes extremely frequent (every 20–40 miles), the DPF may be:
- Partially clogged
- Loaded with ash
- Restricted due to a malfunctioning EGR or NOx sensor
In these cases, a cleaning, forced regen, or diagnostics are required.
Monitoring Regeneration During City Driving
A diagnostic laptop can display live:
- Soot level percentage
- Regen status
- DPF pressure
- Exhaust temperatures
- Sensor performance (NOx, EGR flow, temp sensors)
This helps prevent DPF failures before they occur.
Need Help?
If city driving is causing regen problems, or you need help diagnosing soot buildup, contact us below:
- Phone (Toll Free): (877) 210-3245
- Email: info@truckscanners.com
- Contact Page: https://truckscanners.com/contact/
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