So my car has 78k miles on it, but was serviced at infiniti at 70k miles for a transmission fluid drain and fill. I took my car to an autocross and drove 8 laps really hard. So I plan to drain and fill the transmission fluid. Would I need to do that and drive 100 miles and repeat the process another time? I read some posts about people doing that several times.

 

If your transmission has been serviced regularly one drain and fill should do the trick.