Table 2: Compilation of the relationships between compartment and tunnel concentrations for BC and NOx, calculated based on linear regressions. The last two columns show the average BC/NOx-ratios in the tunnel air and in the passenger compartment air when driving through Södra Länken. Seat Tarraco was defined as an outlier and was excluded in the mean values.
| Model | Cabin /tunnel BC | Cabin /tunnel NOx | Cabin /tunnel NO2 | Cabin /tunnel BC/NOx | Mean BC/NOx inside tunnel mg BC g-1 NOx-1 | Mean BC/NOx inside vehicle mg BC g-1 NOx-1 |
| Volvo V60 | 0.53 | 0.80 | 0.14 | 0.75 | 15.7 | 9.4 |
| Seat Leon | 0.49 | 0.77 | 0.16 | 0.18 | 13.9 | 7.9 |
| Kia Ceed | 0.47 | 0.70 | 0.73 | 0.53 | 12.1 | 8.0 |
| BMW 525 | 0.26 | 0.99 | 0.67 | 0.07 | 10.8 | 1.7 |
| Seat Tarraco | 0.13 | 0.35 | 0.05 | 0.41 | 10.5 | 3.0 |
| Renault Zoe | 0.51 | 0.59 | 0.12 | 0.43 | 11.5 | 8.6 |
| Subaru Forester | 0.73 | 0.69 | 1.02 | 0.99 | 11.1 | 9.5 |
| Volkswagen Passat | 0.57 | 0.89 | 0.46 | 0.62 | 11.3 | 5.6 |
| Audi Q3, bensin | 0.24 | 0.67 | 0.29 | 0.40 | 10.9 | 3.7 |
| Misubishi Outlander | 0.65 | 0.80 | 0.72 | 0.70 | 12.3 | 9.7 |
| Mean (except Seat Tarraco) | 0.49 ± 0.11 | 0.77 ± 0.08 | 0.48 ± 0.21 | 0.52 ± 0.19 | 12.2 ± 1.1 | 7.1 ± 1.9 |