Gasoline direct injection (GDI) engines are becoming the new standard in engine technology; the reduction in fuel consumption, engine size and increase in power have made it so within the next year, GDI will replace the current port fuel injection (PFI) method with regards to global market share. The benefits that come with GDI are accompanied with some penalties in particulate number (PN) emissions. The relocation of the fuel injector causes a reduction in fuel and air mixing time, leading to a dramatic increase in PN when compared to the previous technology. As of September 2017, GDI powered vehicles have been limited to 6x10^11 Particles/km.