Question
Can I run my truck parking heater while driving?
Short Answer
Yes. It runs while the engine is on, but once the engine warms up, the factory heater takes over and the parking heater is unnecessary.
Why Run It While Driving
On a very cold morning, the engine takes 10 minutes to blow warm air. The parking heater gives instant warmth.
Fuel Use
The alternator charges the battery. The heater uses negligible fuel. No downside.
When to Turn Off
Once the engine is at operating temperature, turn off the parking heater. It saves a little fuel.
Result
Running it while driving is safe and common on cold commutes.
References
[1] European Union Regulation (EU) 2015/1188 on monitoring and reporting of CO2 emissions.
[2] European Union Regulation (EU) 2015/1186 on type-approval requirements for motor vehicles and engines regarding emissions.
[3] SAE International J1455: Recommended Environmental Practices for Electronic Equipment Design in Heavy-Duty Vehicle Applications.
[4] FCC Part 15 Subpart C: Intentional Radiators.
[5] ISO 6722: Road vehicles – 60 V and 600 V single-core cables.
[6] U.S. EPA Idling Reduction Fact Sheet for Heavy-Duty Diesel Vehicles.
[7] ISO 8820-2: Road vehicles – Time-lapse current-limiting fuses.
