We have developed the Pele suite of exascale codes for the simulation of compressible and low-Mach fluid flows. We have used both the compressible (PeleC) and low-Mach (PeleLMeX) versions of these codes to simulate a single cylinder of a Reactivity Controlled Compression Ignition (RCCI) engine down to micrometer scales. This suite of codes is open source and are available at the following links: https://github.com/AMReX-Combustion/PeleC and https://github.com/AMReX-Combustion/PeleLMeX.