Otto cycle vehicles with gasoline direct injection (GDI) can reduce fuel consumption by 5–20%. In compliance with current legislation in Brazil, this technology was introduced to the domestic market in the form of a first flex-fuel GDI vehicle in 2013. However, despite gains in efficiency, studies in the literature have shown that GDI engines tend to have higher particulate matter emissions than port fuel injection (PFI) engines. This paper provides measurements of the emissions of GDI flex-fuel vehicles fuelled with gasoline containing 22% anhydrous ethanol (E22), hydrous ethanol (E100) and a 50% mixture of both (E61). The blending fuels were tested in accordance with the recommendations made in the widely known FTP 75 and HWFET cycles. The particulate-matter emissions formed during the combustion process were closely linked to fuel-type properties. The results showed the particles that adhere to sampling filters have higher concentrations of fluorine and carbon and lower amounts of silicon and oxygen, as well as sizes of around 2 μm. The black carbon emissions tend to increase directly with the gasoline content in the fuel. The results also provided evidence that the HWFET test cycle showed a higher emission rate of total particulate matter than the FTP 75 test cycle, and that overall, there were higher emissions for E22 than E100.

汽油直喷（GDI）的汽油机可以将燃油消耗降低5–20％。根据巴西现行法规，这项技术于2013年以首个弹性燃料GDI车辆的形式引入了国内市场。但是，尽管效率有所提高，但文献研究表明，GDI发动机往往具有更高的功率。颗粒物排放量要比港口燃料喷射（PFI）发动机高。本文提供了使用含有22％无水乙醇（E22），含水乙醇（E100）和两者的50％混合气（E61）的汽油所燃料的GDI弹性燃料汽车的排放量的测量值。根据在众所周知的FTP 75和HWFET循环中提出的建议对混合燃料进行了测试。燃烧过程中形成的颗粒物排放与燃料类型特性密切相关。结果表明，附着在采样过滤器上的颗粒的氟和碳浓度较高，而硅和氧的含量较低，尺寸约为2μm。黑碳排放往往会随着燃料中汽油的含量而直接增加。该结果还提供了证据，表明HWFET测试循环显示的总颗粒物排放速率高于FTP 75测试循环，并且总体而言，E22的排放量高于E100。黑碳排放往往会随着燃料中汽油的含量而直接增加。该结果还提供了证据，表明HWFET测试循环显示的总颗粒物排放率高于FTP 75测试循环，并且总体而言，E22的排放量高于E100。黑碳排放往往会随着燃料中汽油的含量而直接增加。该结果还提供了证据，表明HWFET测试循环显示的总颗粒物排放率高于FTP 75测试循环，并且总体而言，E22的排放量高于E100。