Black carbon (BC) is considered the second largest anthropogenic climate forcer, but the radiative effects of BC are highly correlated with its combustion sources. On-road vehicles are an important source of anthropogenic BC. However, there are major uncertainties in the estimates of the BC emissions from on-road light-duty passenger vehicles (LDPVs), and results obtained with the portable emissions measurement system (PEMS) method are particularly lacking. We developed a PEMS platform and evaluated the on-road BC emissions from ten in-use LDPVs. We demonstrated that the BC emission factors (EFs) of gasoline direction injection (GDI) engine vehicles range from 1.10 to 1.56 mg·km⁻¹, which are higher than the EFs of port fuel injection (PFI) engine vehicles (0.10–0.17 mg·km⁻¹) by a factor of 11. The BC emissions during the cold-start phase contributed 2%–33% to the total emissions. A strong correlation (R² = 0.70) was observed between the relative BC EFs and average vehicle speed, indicating that traffic congestion alleviation could effectively mitigate BC emissions. Moreover, BC and particle number (PN) emissions were linearly correlated (R² = 0.90), and compared to PFI engine vehicles, the instantaneous PN-to-BC emission rates of GDI engine vehicles were less sensitive to vehicle specific power-to-velocity (VSPV) increase in all speed ranges.

黑碳（BC）被认为是第二大人为气候强迫因子，但黑碳的辐射效应与其燃烧源高度相关。道路车辆是人为 BC 的重要来源。然而，道路轻型乘用车 (LDPV) 的黑碳排放估算存在很大的不确定性，尤其缺乏使用便携式排放测量系统 (PEMS) 方法获得的结果。我们开发了一个 PEMS 平台并评估了 10 个在用 LDPV 的道路 BC 排放。我们证明了汽油定向喷射 (GDI) 发动机车辆的 BC 排放因子 (EFs) 范围为 1.10 至 1.56 mg·km ^-1，高于端口燃油喷射 (PFI) 发动机车辆的 EFs (0.10-0.17 mg ·km ^-1) 的 11 倍。冷启动阶段的 BC 排放量占总排放量的 2%–33%。BC EFs 与平均车速之间存在很强的相关性（R ²  = 0.70），表明缓解交通拥堵可以有效缓解 BC 排放。此外，BC 和粒子数 (PN) 排放呈线性相关 ( R ²  = 0.90)，与 PFI 发动机车辆相比，GDI 发动机车辆的瞬时 PN-to-BC 排放率对车辆比功率的敏感性较低。速度 (VSPV) 在所有速度范围内增加。