Achieving NOx Emissions with Zero-Impact on Air Quality from Diesel Light-Duty Commercial Vehicles
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe article submitted for review describes simulation-based results regarding NOx emissions. The article in detail describes emission levels that vehicles should meet in order to be recognized as "Zero Impact Emission". The article considers different exhaust system designs to meet the relevant legislative requirements.
The article provides a profound discussion on the presented simulation results. The basis for the conclusions drawn from the results is also solidly based on the cited literature. The presented results are clear and very precisely described.
What is most striking during the review of the article is the very modest (practically zero) description of the adopted simulation methodology. The article does contain a reference to the literature in which the assumptions for the adopted model are described in detail, but the reviewed article refers to the entire issue in literally two sentences, namely: "The design was conducted on virtual basis through simulations. For the simulations, a co-developed Matlab/Simulink based simulation platform (...) was used." (lines 80-84). In my opinion, such a description of the adopted methodology is insufficient. When describing the model, a list of evaluated parameters, assumptions (at least the relevant ones) that were taken into account in the construction of the model could be provided. The same objection applies to the description of the proposed scenarios. Despite the references to detailed descriptions included in other literature (mentioned earlier), I definitely believe that the description of the adopted research methodology (model description, model sensitivity to the introduced parameters, boundary conditions, assumptions for the scenarios, etc.) should be presented in the article and described in greater detail in the Materials and Methods section.
The introduction section lacks references to current literature focusing on simulation studies. The text could also be enriched with a critical evaluation of the assumptions of other authors' models used in the analysis of toxic compound emissions.
A slightly more substantive explanation regarding the adoption of a specific type of vehicle (N1 Class III LCV) in the simulation studies, even by providing the share of this group of vehicles in the overall vehicle structure, could make the research more credible.
A broader discussion regarding the proposed (adopted) exhaust gas aftertreatment system technology would also be appreciated. If the discussion regarding the general layout and capacity of individual exhaust system components were conducted in the same way as the discussion regarding the power (and type) of additional heating components, the article would be much more readable and the presented discussion less limited.
The presented observations and comments are intended to improve the reception of the information presented in the manuscript and to expand the boundaries of scientific discussion on the discussed issues.
Comments on the Quality of English LanguageThe language used in the manuscript is correct in terms of syntax, grammar and spelling. There are some minor errors such as incorrect use of capital letters (e.g. points in lines 67-74) or duplicated spaces between words (e.g. after the reference to literature in line 294). It is recommended to review the text to eliminate such errors.
The authors use long, often complex sentences in the text. This may, to some extent, make it difficult to receive the presented content. In this respect, I would also recommend proofreading the text in order to simplify (shorten) some sentences, in order to improve the clarity of the text and make it easier to read.
The last issue concerning the language is definitely too many abbreviations for expressions used in the text. All abbreviations are correctly introduced, sometimes even several times - probably to facilitate reading, but their number makes it difficult to clearly analyze the presented information. At this point, the authors could try to eliminate the least frequently used abbreviations, also including the nomenclature in the table would be beneficial for future readers.
Author Response
Please see the attachment!
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for Authors1. The Introduction should comprehensively reflect relevant research related to this study, incorporating the latest literature from 2024 and 2025.
2. The novelty of this study must be explicitly stated in the final paragraph of the Introduction. Specifically, the study’s contribution to the engineering literature should be clearly articulated. A critical aspect to address is how this study differs from and builds upon the following works:
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- “Challenges and Solutions to Meet the Euro 7 NOx Emission Requirements for Diesel Light-Duty Commercial Vehicles” (have 2% self-citation)
- “How to Define and Achieve Zero-Impact Emissions in Road Transport?” (based on this study by authors)
After presenting the literature review, the study’s primary objective and the research gap it aims to fill should be clearly stated.
3. Methodology should be concise, structured logically, and sufficiently detailed to enable other researchers to replicate the study. References may be included where necessary.
4. The Results and Discussion section needs significant revision. The results should be presented in a quantitative manner, thoroughly discussed, and compared with findings from existing literature. Speculative interpretations should be avoided.
5. If feasible, the uncertainty in the results should be addressed, particularly in relation to the study’s key findings.
6. In addition to summarizing the main findings, the Conclusion should highlight research gaps and potential future research directions identified based on the presented results.
7. Finally, the study appears to rely heavily on Reference 11 ("How to Define and Achieve Zero-Impact Emissions in Road Transport?"), which makes it resemble a review paper rather than an original research study. This issue needs to be resolved by the authors to clarify the study’s originality and contribution.
Author Response
Please see the attachment!
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsThis manuscript has presented powertrain solutions to achieve zero-impact NOx emissions with an N1 class III diesel light commercial vehicle. However, the manuscript requires MAJOR REVISION before it is considered for publication. Thus, the authors should revise the manuscript accordingly. The following hints may help the authors：
Q1: The writing and grammar should be extensively improved. The current version of the manuscript is hard to read because it is very poorly written. I encourage the authors to work with an English speaker in order to improve the readability of the text. In addition, the tense of a sentence should be improved. Many grammatical errors were found.
Q2: In paper, please avoid the lump literature, such as [1-4], [7-9] and so on, summarize the main contribution of each references paper in separate sentences. The reference style should be checked again according to the journal standard. Some references should be added and considered such as Fuel, 2021,290:120039.
Q3: There are many abbreviations in the article, and it is very useful for the author to add a nomenclature. Abbreviations appearing for the first time in an article should be used in full, and the abstract is no exception.
Q4: The Discussion and Results section is written too simply, and the authors are advised to rewrite the Discussion and Results section. This paper cannot provide meaningful conclusions to the author.
Q5: The paper lacks innovation. The authors must highlight their own findings from literature review.
Q6: If possible, the author should consider more working conditions.Why did you select the operating conditions? The experimental methodology should be also explained. How do you ensure the repeatability of your measurements? If possible, the author should consider more operating conditions.
Q7: Why did the author choose this fuel? According to the review experts, there are many similar fuels used in diesel engines in the current research. What are the differences between the fuel used by the author and other fuels? If only to replace the fuel, does it appear that the article is very one-sided and very empty?
Q8: If possible, the author should consider the effects of other fuel on NOx emission.
Comments on the Quality of English LanguagePlease see the Comments and Suggestions for Authors.
Author Response
Please see the attachment!
Author Response File: Author Response.pdf
Reviewer 4 Report
Comments and Suggestions for AuthorsThe article concerns solutions that should be used in diesel light-duty commercial vehicles to achieve zero impact on air quality in terms of nitrogen oxides. The article concerns an up-to-date and important topic. However, as a reader, I would like to know why the authors limited their analyzes only to NOx, omitting in particular PM, PN and CO2. The limited literature analysis also caught my attention. I ask the authors to expand it, especially since they indicate that they have performed an extended literature study. I lack an explanation of why the methodology described in [11] was chosen, what the pros and cons were, and what the alternatives were. I miss defining the limitations of the analyzes performed. Were the solutions used associated with any side effects, how did the emissions of other exhaust components, carbon footprint or energy consumption change? I recommend that the article include a list of abbreviations and symbols used in the text.
Specific comments:
1. Figure 2: please explain what 'Brenner' means, I think non-European readers will not know what it means, and also what the percentages in the driving cycle column mean.
2. Figure 4: what does 'Result combined' mean, complete the unit.
3. Figure 5: why only 25% of the payload was used?
4. Table 2: I have doubts about the high soot emissions (ca 0.3 g/kWh), over 10 times higher than HC, please check it.
5. Please compare the competitiveness of solutions for heating the catalytic aftertreatment system using electricity and diesel-fuel burner.
Author Response
Please see the attachment!
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
Comments and Suggestions for AuthorsAll questions are answered. Thanks to the authors for their great effort.
Reviewer 3 Report
Comments and Suggestions for AuthorsThe authors have carried out a thorough and careful revision and the revised manuscript improved a lot in terms of technical quality and language. Therefore, I would recommend it for publication in the Journal.
Reviewer 4 Report
Comments and Suggestions for AuthorsIn the revised version, the authors have taken into account all of my comments. In the current version, I recommend the article for publication.
