This a separate Crew Chief exe which will use separate data files (except for the voice files which are shared) - c:\Program Files (x86)\Britton IT Ltd\CrewChiefV4\CrewChiefRC.exe There are a number of internal changes which should be invisible and these improvements a simple "Set up wizard" which prompts you to enter your name and then select "Very Important Properties" you can disable various speech commands, this will improve recognition accuracy a bunch of small bug fixes add "What's my car number?", "What lap am I on?" checking Property Quasi American Units will use MPH and gallons for ovals and stock car racing even though you have checked Use metric iRacing: add "Change front tyres", "Change rear tyres" iRacing: fix starting/restarting grid side, report more information about opponents (club, incident count) and estimated lap time for your class