I have the same treadmill and FINALLY after months of searching found my manual. Here are the instructions:
1 . Turn off treadmill
2. With the safety pull pin inserted, press and hold the POWER button for 5 seconds or until SI appears in the INCLINE window.
3. Release POWER button. You are now in kilometers per hour.
4. Repeat steps 1-2 to convert to miles per hour
I am pretty sure this treadmills come set on MPH. I hated not knowing how far I was running.
sara, February 2009