Wife's old Cavalier drive somewhere between 0 and 17 miles with no coolant. I was outside when she got home from work and noticed an odd stain on her front bumper. Dried coolant. Popped the hood and there was coolant everywhere. Overflow tank completely empty, no rad. cap on these but when I opened the drain, maybe a cup or so is all that came out. Engine still running, no smoke or funny noises or anything like that I could see. I didn't look at the temp gauge because she'd already shut the car off, and she of course didn't look at it on the way home. Replaced the leaking pipe, refilled with coolant, and that thing ran for over a year until the tranny finally gave out at 237,000 miles. That engine has proven itself over the 10 years she drove it to be completely indestructible.