Effect of lubricant on the formation of heavy-duty diesel exhaust nanoparticles

Kati Vaaraslahti, Jorma Keskinen (Corresponding Author), Barouch Giechaskiel, Anu Solla, Timo Murtonen, Hannu Vesala

    Research output: Contribution to journalArticleScientificpeer-review

    112 Citations (Scopus)


    The effect of lubricants on nanoparticle formation in heavy-duty diesel exhaust with and without a continuously regenerating diesel particulate filter (CRDPF) is studied. A partial flow sampling system with a particle size distribution measurement starting from 3 nm, approximately, is used. Tests are conducted using four different lubricant formulations, a very low sulfur content fuel, and four steady-state driving modes. A well-documented test procedure was followed for each test. Two different kinds of nanoparticle formation were observed, and both were found to be affected by the lubricant but in different way. Without CRDPF, nanoparticles were observed at low loads. No correlation between lubricant sulfur and these nanoparticles was found. These nanoparticles are suggested to form mainly from hydrocarbons. With CRDPF, installed nanoparticles were formed only at high load. The formation correlated positively with the lubricant (and fuel) sulfur level, suggesting that sulfuric compounds are the main nucleating species in this situation. Storage effects of CRDPF had an effect on nanoparticle concentration as the emissions of nanoparticles decreased over time.
    Original languageEnglish
    Pages (from-to)8497 - 8504
    Number of pages8
    JournalEnvironmental Science & Technology
    Issue number21
    Publication statusPublished - 2005
    MoE publication typeA1 Journal article-refereed


    • diesel engines
    • diesel exhaust
    • nanoparticles
    • fine particles


    Dive into the research topics of 'Effect of lubricant on the formation of heavy-duty diesel exhaust nanoparticles'. Together they form a unique fingerprint.

    Cite this