Q Why are some 16-bit roms 160kb in size, while others are 192kb?
An ecu image consists of particular areas that are volatile, meaning they are erased every time you reset your ecu (by disconnecting the negative terminal on your battery or using a program like Ecuexplorer to reset). These areas of ram are used by the ecu to store temporary data, such as long-term fuel trims, current sensor values, and the like. The data stored here is not necessary for tuning your rom, so the ram data itself is not downloaded. The 160kb file represents a 16-bit rom without the ram area included. The 192kb download is also 16-bit and includes the area of ram, but with the values essentially “zeroed out”. So which should you use? RomRaider will work with either size file, so you don’t have to worry about it. If you are doing some editing or viewing with a hex editor, you may find it more convenient to use the 192kb size, as the address locations will match up with the definitions file without calculating anything. Recent versions of Ecuflash will download 16-bit roms as 160kb files, whereas Ecuexplorer (which uses an older version of Ecuflash) downloads 16-bit roms as 192kb files.