If I totally run out of gas with my 2005 Prius, will it still run until the battery dies too? I am just curious. I am leaning toward the latter.
Yes, obviously, but not instantly. You can go a mile or two, depending on the weather, speed, and the charge in your battery. Now that I have said that, don't do it. Treat your Prius just as you would any other car if you run out of gas. Use the battery to get off the road and to a safe place. Once you run down the battery, the car will shut off. You can start again, but each time will draw down the battery. It's not good for the battery, and if you take it down far enough, your dealer will have to send for the regional HV charger to get it charged again. You don't want to do that. Tom
I know you are simply seeking information about a speculative event, but please take great care not to be in the situation of relying upon or using the HV battery after you have run out of gas. There are some severe penalties for using the battery once you have run out of gas. You are likely to cause irreparable damage to the HV battery, and you may negate the warranty. If this post doesn't get your full attention, please read through this thread from about one year ago: Impacts of Running Out of Gas.
Responsible posting posting please. You ARE NOT "likely" to cause irreparable damage. You -may- cause damage to the battery, if you keep trying to use it after it kicks you off. But to cause damage you have to be stupid about it. Many many many owners have run out of gas. Some even do it intentionally to "measure" certain power levels etc. Very few have -ever- killed or even shortened the life of the traction battery. It's best not to run out. If you do, pull off the road and get gas. It's a car. Treat it like a car. It runs on gas, so make sure it has gas to run on.
+1 The only instrument more in the driver's line of sight than the speedo is the gas gauge so why would you run out of gas? How far can you drive a F150 or a Chev Impala when it runs out of gas? The only battery failure I have heard about in a gen II Prius was a person who ran out of gas and kept re-booting until he could drive no further. He was trying to go 10 or so miles on the battery, no way! I think from memory within a month he announced his battery had failed. This was an extreme event of running the battery down to the last. You can safely drive to the side of the road without gas but why run out? As Okie... said, fill at 2 bars and keep smiling.
If you needed another reason, the fuel pump is an integral part of the fuel tank assembly and it's cooled by the liquid gasoline surrounding it. It's no longer submerged below 25% full. The manual recommends filling at 25%. I always fill at two pips and I don't even have the bladder. (The bladder is, as far as I can tell, North America only - unfortunately so is the coolant thermos.)
His tone was a bit alarmist but not irresponsibly so. By its very nature draining a NiMH battery does reduce its remaining life, and since it doesn't grow back I'd call that "irreparable damage". Maybe not significant (0.1%? 10%? we don't have a good way to measure the remaining life), but not zero either. Anyway, OP: just don't run out of gas. It's really dumb.
Maybe there needs to be a sticky, "Don't run out of gas". After all, it seems as though some simply refuse to read the manual, or consider common sense from experience in other cars, or read the infinate number of previously posted threads on PC. Put in simpler terms? Uh, can't. Still, being a risk taker, I've lucked out over the years. If I ever ran out, I'd sure never admit it.
I'm not so sure about that. If true, I should have burned out my fuel pump tens of thousands of miles ago. If I know I will need fuel before getting to my very distant destination, I check GasBuddy.com and see where the cheapest gas will be on the route such that I've not used more than maybe 10.5 gallons. It still leaves me a gallon plus spare (yes, I make sure I fill it every time. If I'm just doing 'around town' driving, I'll definitely wait until 10 to 10.5 gallons used, sometimes more. I've never run out of gas nor had problems. The 'cold weather mileage hit' already drags my '10.5 gallon tank distance' from 575 to 475. I have no desire to drop it to 400 when the temps are in the 20s F and almost 300 at 0F simply because I'm not dipping into the 'last' ~ 3 gallons. It will be interesting to see if the 2010 has water vapor problems since there is no bladder. That is the reason not to go below 25% (8.9 gallons used) in the winter. It could be they have some other technical solution to tank water vapor and vapor lock or freezing in the fuel lines. The bladder guarantees there is no 'air' space above the gasoline. No air space, no water vapor.
The fuel pump is cooled by gas. That doesn't mean it will die instantly when you run down the tank, but it doesn't mean it's good for it either. Tom
EV mode will cease when you get to 2 bars on the battery display. At that level, you are NOT damaging the battery. In fact, I have seen my car continue in auto EV (near dead stop traffic at road construction) even at 2 bars. ANY request for other than 'idle' speed will kick on the ICE. As others noted, you can apparently keep restarting and forcing the battery down. That would NOT be a good idea. IF you found yourself in an 'out of gas' situation AND you could see a station 1/2 mile away and not up a hill (or maybe there is a rise you can crest and continue downhill in 'glide'), you could turn off all 12V accessories (The 12V is charged from the big battery) and creep (WITH FLASHERS ON if there is traffic) as long as the battery is above 2 bars. If the car cuts out at 2 bars, put it in Park and walk to the station. If you have no idea if there is gas nearby, call AAA as soon as you can park safely.
I didn't mean to suggest that it isn't cooled by gas. I am only questioning the claim that there will be no cooling if you go below 25% full.