What happens after Blinking Pip (Fuel Gage)?

After having to replace a fuel pump in a non-Prius because I typically ran the gas to near empty before filling up, I was told that you shouldn't run the tank to near empty in any car because the fuel pump is kept cool by the gas in the tank. - Just a word to the wise.

 

You die.

 

I don't understand why you would ever let the tank run that low. Thirty miles PAST empty? The fuel gauge is there for a reason. As mentioned before, you risk damage to the fuel pump, and it's just bad practice because you could run out of gas and be stranted at any time. I start thinking about getting gas as soon as my tank goes below 2 pips.

 

Yeah, I'm also trying to figure out what is the point of running the fuel down to the critical stage of empty.
is there better mileage down at the bottom of the fuel tank?

 

I think he was just curious of there are any further indications. There have been several replies to his post but as of yet no attempt to answer the question.

 

In a Gen 2, the car become very quiet, the dash board lights up, and you can't go over 35. You pull over and start walking to the nearest gas station. Three times, as the Gen 2 does not recognize less than 3 gallons.

While that is what happened to me, I cannot recommend it ever happening to you.

 

Yes, actually. If you think of fuel as extra weight then there is benefit of driving the car with an emptier tank.

While what follows is not meant to be generally transferrable to a Gen III, I will share my experience with a Gen II As one who regularly, I mean REGULARLY, drives 100 - 150 miles past the point of when the last pip starts to flash, I can speak from experience. I ran out of gas once, during the first couple of months of owning my Gen II. The car gave one long beep and then I was in EV mode. I took the battery down to two purple bars and then it wouldn't move any further. The frustrating part of the experience was that, while in EV mode, I drove past a gas station that had just closed a couple of days before.

The point I am trying to make is that the car is designed not to allow you to cause any damage to the vehicle. Please note that I have a lot of experience with the car since then and the most I have ever put into the tank after my going all those miles beyond the last pip flashing is 11.2 gallons. again, this is with a Gen II, and all the attendant caveats with each car being a unique beast with respect to how much fuel is actually in the tank.

Now, before all the flamers get started, I am not recommending to anyone, especially those not in a Gen II, to automatically adjust their refueling habits. I've had over 8 year's experience with my car and know how it operates. Just because there are some who would never consider going beyond a quarter tank it doesn't mean those of us who try to get more mileage out of a tank are wrong, or otherwise causing damage to the car.



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Yes, the engine will. You want to pull over as soon as you can because if you run down the HV battery, the dealer has to order an HV Battery charger from Regional. $$$

 

??? And how, exactly, do you know this? I have a hard time believing that the dealer has to order a special charger. If you run down the battery to the point to where it no longer will propel the car, let's say for the sake of the argument as you where pulling into a gas station, you couldn't fill up and have the engine start to recharge the battery?

I just don't buy into that crappy of a design. Toyota has to have designed the car knowing that there may be times where running out of gas could happen. If that were not the case then they would have put much stronger warnings in the manual. I just did a quick read of the Gen III manual and couldn't find anything indicating what you have suggested. There is a section on not damaging the vehicle but it speaks to things like turning the steering wheel too far, etc. Again, nothing about running out of fuel and needing have the battery recharged with a special charger.

If there is more information from Toyota then please enlighten me and I will shut up about this.



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I operate all my vehicles to an empty tank. The "Miles to Go" approaching zero. I haven't seen any of the manuals saying not to do this. The gas gauge on all vehicles, Prius included, has a margin for error as we all see when we fill up when "empty" per the gauge and find there is a gallon or two in the tank.

On the Prius, I received no warning from the dealer on check out about driving until the fuel gauge was blinking and warning said "0" miles. Don't see any warning in the manual.

 

On my current tank, I've driven 692 miles and still have 2 pips showing. But it doesn't make any sense to drive any further. That's plenty far. At 700, I'll be stopping to refill.

What would I gain from allowing it to go lower? True, you can damage the fuel-pump and battery-pack from continuing to drive after running out of gas. I see no benefit from further distance. Getting 100 MPG is plenty rewarding.

 

Just one question = What will start the engine? In a Prius it is the HV battery that supplies power to one of the Motor/Generators to start the engine. A "run down" HV battery results in a dead Prius.

JeffD

 

http://www.mastertechmag.com/pdf/2010/10oct/201010-outofjuice.pdf

He says pretty much what I said, but from the independent mechanic's point of view

 

The single pip keeps blinking. The next warning will be the Electric Power Steering warning light turning on, meaning that car is out of gas AND the traction battery has been depleted to the minimum that the car will allow. The GenIII is less user friendly on this than the GenII, which gave enough warning to find safe parking before the battery depleted.

Bob Wilson ran cars out of fuel for fun and sport. See his thread [WARNING] Running out of gas (Gen III).

 

Who already has a HV Battery charger laying around? It would have to generate different Voltages for Gen 1, Gen 2&3&v, and c. You only need it if the driver runs out of gas, then keeps driving until the car stops.

If you had some way to start the engine, yes. In a Prius the HV battery starts the engine.

 

That's an excellent article for all Prius owners to read, even if one doesn't run the tank near-empty.

 

I think you missed my point --- you shouldn't need to have an HV battery charger at all, unless it is an extreme case where you continued to deplete the battery after it stopped being able to provide traction power.

If you drive to that point, fill up with at least 3 gallons (Gen II; don't know what that should be for Gen III), the ICE should start. Toyota's engineers designed the system to keep reserve in the hybrid battery even though it won't continue to provide traction power. And it is exactly that design feature that prevents damage to the hybrid battery system.

However, with users of all products having that unique capability to break just about anything, there may be cases where that engineering design is defeated. My advice: if you do find yourself in a situation where you have run out of fuel and can't EV mode to a gas station, fill the tank with at least the minimum amount of fuel required to get the ICE back up and running. Don't do things with the car that would continue to deplete the HV battery until you get the right amount of fuel back into the tank.

Paul's article is great and we should remember that this is written from a mechanic's POV --- they get the pleasure of seeing just how bad things can get. Running out of gas and having to add more to restart the ICE doesn't necessarily mean you are going to have to go the HV battery recharge route.





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