Speech recognition is possible in other languages. You need to copy "%ProgramFiles(x86)%\Britton IT Ltd\CrewChiefV4\speech_recognition_config.txt" to  [user]/AppData/local/CrewChiefV4/ and translate the phrases, for example

HOWS_MY_ENGINE = comment va mon moteur
or
WHATS_MY_FUEL_LEVEL = wieviel benzin habe ich noch

There are more details in speech_recognition_config.txt

Translating Crew Chief's speech phrases is a much bigger task, see Customising Voice Packs.