Investigating Particulate and Nitrogen Oxides Emissions of a Plug-In Hybrid Electric Vehicle for a Real-World Driving Scenario

Round 1

Reviewer 1 Report

Well written and developed work focusing on a very related topic in relation to the delivery of hybrid vehicles. Therefore, I recommend the publication of the work.

Author Response

Dear Reviewer 1,

thank you for your feedback.

Kind regards,
Mario Feinauer et al.

Reviewer 2 Report

1. It is necessary to include the variables table where can be identify each one.
2. Include the characteristics, specifications and calibration method for the instruments.
3. Improve the graphs 6a, 6b and 14 in order to have a better visualization of the information presented.

Author Response

Dear Reviewer 2,

thank you for your comments and suggestions.

1. We added table 2, which gives an overview of the relevant measuring systems and the respective measurement parameters.
2. Please find the added information regarding the testing equipment and calibration methods in section 2.3. 
3. The mentioned graphs have been revised and improved regarding the visualization of the presented information.

Kind regards,

Mario Feinauer et al.

Reviewer 3 Report

The work is clear and well structured, but could improve in the following aspects:

The references can be improved as well as the introduction. Please make references to other authors using PEMS.

In figure 1 it is not necessary to put decimals in the legend.

Please indicate the meaning of KAT in figure 2. Could it be exhaust catalyst?

How was the fuel consumption obtained? Could you explain the type of fuel mass flow sensor (is it specific to the vehicle or external)?

 

 

 

Author Response

Dear Reviewer 3,

thank you for your feedback and your comments.

• Please find our additions in the introduction section with respective references regarding further PEMS measurements.
• Figure 1 was revised in accordance with your comment. Also, the vehicle speed ranges have been added.
• Figure 2 was also revised. Yes, it meant the catalyst but now the term is fully written.
• We added 2 sentences in section 2.3, lines 158-161: "Fuel consumption is measured using a flowtronic sensor series S8005 (Gregory Technology GmbH), which is an external sensor. The measuring range is between 0.1 l/h and 250 l/h and the measuring accuracy is ± 0.5%."

Kind regards,

Mario Feinauer et al.

Reviewer 4 Report

The authors emphasized the really important topic related to the upcoming new euro7 emission standards related to hybrid vehicles.

 

There should be corrected as follows:

 

 

- once you use extra-urban part and once rural (eg. 69 and 82 paragrphs) please unify this issue,

- it would be beneficial and more clear for the reader if you will distinguish the road section on figure 1,

- one of your main motive to perform research was sentence: "One influencing factor is, for example, that driving 38 in electric mode can lead to peak CO and NOx emissions in motorway driving situations 39 due to cold start of ICE in relation to not sufficient temperature of the catalyst", - then you actually indicated that "The comparison shows that the Stuttgart route has a relatively high share of 105 urban and rural parts while the motorway distance share is relatively low" - so that this is at the same time motivation and limitation of the research - this should be mentioned in the contemplations,

- the accuracy of the used PEMS system should be summarized in the table.

 

In addition to the above issues, the work presents a good level and will be a valuable addition to existing literature studies.

Author Response

Dear Reviewer 4,

thank you for your feedback and your comments.

• We revised the manuscript so that now the term "rural" is used consistently.
• The test route does not have fixed limits for the 3 sections. As described in line 92/93 and 110-114, the sections are vehicle speed dependent. We included this information also directly in Figure 1, by adding the vehicle speed ranges of the respective section.
• We considered this aspect in the discussion part regarding the increased PN emissions for hybrid mode driving compared to sport mode driving during motorway driving, please find the added paragraph at line 300-308.
• We added information in section 2.3 regarding the PN PEMS measurement accuracy and mentioned a respective reference (lines 138-141).

Kind regards,

Mario Feinauer et al.