Engine preheating under real-world subfreezing conditions provides less than expected benefits to vehicle fuel economy and emission reduction for light-duty vehicles

Miska Olin, Ville Leinonen, Sampsa Martikainen, Ukko-Ville Mäkinen, Henri Oikarinen, Santtu Mikkonen and Panu Karjalainen

Applied Energy, 2023, vol. 351, issue C, No S0306261923011698

Abstract: Six light-duty vehicles, both gasoline- and diesel-fueled, were driven a prescribed 13.8 km route in a real-world low-traffic environment under Finnish subfreezing winter conditions (−28 ... −10 °C). Cold starts, hot starts, and starts with different preheating strategies were used. Fuel consumption and emissions of particles and nitrogen oxides (NOx) were examined by a chasing method with a mobile laboratory. Both electric preheaters (0.3–1.2 kW) and fuel-operated auxiliary heaters (5 kW) were used in the experiments where a cold engine was preheated before starting. While most vehicles showed potential for reducing fuel consumption and emissions of particles (PM), black carbon (BC), and NOx during hot starts compared to subfreezing-cold starts, the benefits of preheating were relatively small and limited to only a few vehicles. The fuel consumption for the 13.8 km drive decreased less than 4% with one gasoline vehicle and one diesel vehicle by preheating. These two vehicles are both equipped with a fuel-operated auxiliary heater, and taking the fuel consumption of the heater during preheating into account leads to about 30% higher total fuel consumption, canceling the preheating benefit out. These two vehicles also showed the largest reductions in PM, BC, and NOx emissions achieved with preheating, e.g., the PM emission reductions being 72% (the gasoline vehicle) and 24% (the diesel vehicle). Whereas the NOx emission reduction for this gasoline vehicle was 41% when considering only the drive, it decreases to 15% when the NOx emissions from the auxiliary heater during preheating are also taken into account. High particle number (PN) emissions from all vehicles and NOx emissions from the diesel vehicles were detected. The PN emissions of particles larger than 23 nm were up to 2 orders of magnitude higher and the NOx emissions up to a factor of 21 higher than the corresponding limits in the European regulations for type-approval of new vehicles. The PN emissions did not depend on the start types; thus, no benefits to reduce them with preheating were detected. The limit-exceeding PN emissions are partially explained with the used measurement method for PN taking both nonvolatile and semivolatile particles into account, whereas the regulations take only the nonvolatile particles into account. The PM emissions were also observed to consist mostly of semivolatile material in most of the cases, organics being the main component of the semivolatile material.

Keywords: Cold start; Vehicle emission; Particle emission; Real-world driving; Subfreezing conditions (search for similar items in EconPapers)
Date: 2023
References: View complete reference list from CitEc
Citations:

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0306261923011698
Full text for ScienceDirect subscribers only

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:eee:appene:v:351:y:2023:i:c:s0306261923011698

Ordering information: This journal article can be ordered from
http://www.elsevier.com/wps/find/journaldescription.cws_home/405891/bibliographic
http://www.elsevier. ... 405891/bibliographic

DOI: 10.1016/j.apenergy.2023.121805

Access Statistics for this article

Applied Energy is currently edited by J. Yan

More articles in Applied Energy from Elsevier
Bibliographic data for series maintained by Catherine Liu ().