LOTS depends on how "sweet" the motor is ...and how much compression it has.

SWEET ? ... how sealed-up-tight it is. I must have a sweetie-pie 4 banger. The last oil I dumped was over 4k miles ...and it had barely changed color. That just-over 9k mile change ... it STILL looked good .. but it was nearing winter-time and I put in a load 5-30.