Dear Authors:

Thank you for your careful consideration of the referees’ comments. I accept this manuscript for publication after the following minor recommendations have been addressed.

~Ellie

Main Text
Page 2 lines 32-33 “for example, inclusion of semi-volatile POA without SOA formation from IVOCs and aging reactions degraded model performance vis-à-vis total OA mass.” Please include the reference for this result.

Page 8 line 1: “Biogenic SOA was not aged.” Although the reason is included in the conclusions, it would perhaps be better to mention that here as well.
Page 13 line 32-pg 14 line 3 “Comparison of the POA predictions from the VBS-IVOC model to ambient measurements made by Ban-Weiss et al. (2008) suggests that the on-road gasoline POA in the model may be over-predicted by a factor of 2, although this under-prediction did not significantly change the gasoline/diesel contribution to OA.” This sentence is very unclear to me. The POA is too high in the model but then the under-prediction is discussed. Should this be over-prediction?

Pg 15 line 19: This should reference Section 3.4

Page 17 line 21: Is 13 the domain average? On page 13 line 26-27 a range for the gasoline contribution to OA of 10-20 times diesel is given. Please clarify.

Supplement
ALK5 is not included in table S.2 despite its reference in the caption and in the main text. Please update the table.