Originally Posted by bigjae1976
I use S4 at the track. You still get the rev matched down shifts so you aren't wasting your clutch discs but its not nearly as rough as S5. An S4 up/down shift won't upset the car in places where S5 would.
Not sure why you would use S3, that would upset the car more than using S5/6 on a downshift.
I started using S3 because I simply forgot to change it back in the day. When driven hard, S3 does perfect rev matched downshifts, and upshifts are pretty fast without any sudden jerks during shifts. It's very seamless. My instructor, who had an E46 SMG was commenting on how smoothly the car upshifts. S5 was way to jerky when I tried it. I have used S4 and thought it was find too.