So this morning I finally burned the last of the gas in our Prius Prime Plus and a warning message flashes up about "Hybrid System Stopped" and "Steering Power Low". Near as I could tell, I'd run a little over one gallon (64 miles / 54 MPG) on "empty" but sad to say, I don't have the exact number. The car became a rolling inertial mass and I pulled into a parking lot where I added the spare gallon and then it got interesting. In the Gen-3, turn the car off; add the spare gallon, and; back on and it would start the engine and away you'd go. Only this time, it would not start the engine and kept displaying: Hybrid System Stopped Steering Power Low To get rolling again, I removed the 12V battery ground for about 30-60 seconds and reconnected. Fortunately I'd bought a leather man multi-tool for this car on Saturday. Sad to say, I did not think to buy a cheap LED flashlight, small crescent or vice grips, nor the tire patch kit (on my 'to do' list.) Reconnecting the ground and tightening the clamp screw, everything started up and I was on my way to a nearby gas station. At the station, the pump first clicked on 10.4 gallons. My usual practice is 'two clicks' which brought it up 10.7. Add the gallon from the spare can gives 11.4-11.7 gallons total. The spec says 11.4 gallons. There was no indication when the car actually runs out of gas. It simply became an inertial mass when "Steering Power Low" is displayed which is consistent with the Gen-3. However, the Gen-3 would suppress the power flow arrows before the alarm giving me time to use the traction battery to reach a safe parking place. Also new, is the need to do a 12V power-ON reset by removing and reattaching the 12V ground wire. I only had a spare gallon can and don't know if adding more gasoline would resolve the problem. Regardless, if you don't know about the 12V power-ON reset, you might have to suffer the cost and delay of a tow. Bob Wilson ps. Miles to empty is still showing 530 miles. I'm going to throw a charge on it and see what happens.