adding gas while prius is on?

Agreed.

Tom

 

How about providing an assist to those who do not want to lose what they've gained by getting the car to stage 4?

What is the gain/loss involved in turning off the Prius vs. leaving it in Ready mode when you've already reached stage 4? If you turn off the car, then how long before you can get back to stage 4 operation? Do you still need to wait for the ICE to cycle and then also come to a complete stop (foot on brake) for X seconds before you get back into stage 4?

Tom? Bueller? Anyone?

 

I was thinking you should expect about the same heat loss with the car in ready (and presumably not idling) vs OFF - but it's possible the heat lost would be even less when OFF since the car would have used the coolant thermos.

I think it's illegal in Canada so its a moot point anyway. That and I make it a point not to idle when parked.

(Here is another thread on the same topic)

 

I'm afraid I just don't see any increased danger. The car is designed to keep fuel safely contained. The exhaust system remains hot enough to ignite any fuel that touches it for some time after the engine is turned off. There are all sorts of motors that actually turn on exactly when you turn the ignition off. Opening the door turns on the interior light.

The engines in all of the cars entering and leaving a gas station are running. What difference does it make that the cars with the hoses attached are running or not?

The biggest danger at a gas station is from filling open gas cans. The next biggest danger is from other drivers who can't manage the traffic.

As for valves reconfiguring the fuel system, I'll have to check the Toyota documentation. Just as a trial balloon, assume that there is a leak in the fuel line from the gas tank to the engine. When the car is off, we can assume that the fuel pump in the tank is disabled, so the leak would be less with the car off. But if the car has a leaking fuel line, it's already extremely dangerous. Connecting the gas station hose isn't going to make much difference if the car is already leaking gas.

One reason to turn off the engine at a filling station is that the car is less likely to take off on its own. So if a car is running, the brake isn't set, and the gear lever gets moved into gear (kids playing with it?), then the car could take off out of control. I can imagine this happening with some cars, but the Prius?

 

Debate all you want. Two facts are unarguable:

1) The fuel system valving reconfigures for refueling when shut down.

2) It is illegal to refuel a running car in most locations. Being in Ready is considered running.

Tom

 

Yes, it's illegal. Don't do it unless you are forced to (dead battery for example).

Cellphones don't ignite fuel vapors. The mythbusters proved that beyond any shadow of doubt. They even shorted the battery manually with no fire! "In the radio industry" we have "intrinsically safe" radios, often speced for use in explosive atmospheres. But these are 2-5 Watt handheld radios, not 0.6 W cellphones.

If you shut off the Prius (even when fully warm), when you restart it will idle for 10-20 sec. in an automatic cycle to ensure the cat. is warm. So with Pearl, that would be about 0.4 CC of fuel (based on about 1 l/hr, which is what Pearl consumes at idle). You will have to make the decision of whether that is significant or not vs breaking the law/possibly putting yourself and others at risk!

I'm still not entirely sure what actually causes the fueling fires I've seen on video. It -may- be static discharge, though that is a low energy spark and usually doesn't ignite fuel vapour. At any rate it would happen whether the car is on or not. I'm more suspicious of the cat. and exhaust sparks or mild backfires.

 

My pet theory is that this myth was put about by the gas stations but the real reason was that they were worried that cellphones would interfere with the electronics in the (early) gas pumps, and therefore the customers would be able to cheat the gas stations instead of the other way around

 

Most definitely static discharge, as in this example:
[ame=http://www.youtube.com/watch?v=b3x-8tj49ac]YouTube - Gas Pump Fire[/ame]

About 3/4ths of gas station fires happen to women because women are much more likely than men to start the pump, get back into the car, and then return to the pump while it is running, as in the video.

qbee42 has laid out the other facts. Leave the car OFF when refueling, and stay at the pump with your hand on the nozzle.

 

The law about turning off while refueling was designed for those real gas guzzlers.... some of those would never fill if idling. Oh, and no shag carpetting at filling stations would be a good safety tip.... I'm on a roll

 

Obviously not going to cool off much. I was just trying to prevent the ICE from running for a minute or so when I turn it back on.

 

There was another thread on this topic a little over a year ago. I'll paste a comment I made there:

A while back someone (Hobbit, I think) suggested that the various relays and switches in the Prius electrical system could be potential spark sources.

Some of you say, "I've never had a problem." Anyone that's ever had a problem at one time could have said that.

Coming from a long-time member of the fire service: Please turn your car off when you refuel. There is virtually nothing to be gained from leaving it on. View it like a risk management professional might. The probability of a problem is small, but the consequences are huge. Use the simple and easy risk reduction step that's literally at your fingertips: the power button.
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As a fuel mileage fanatic, I dislike the (seemingly useless) obligatory after-startup ICE-on period as much as anyone. But folks, it just isn't worth the risk.

 

Ummm.... it's still a car. Shut off your car when you fill up with gasoline. While I appreciate all of you who are concerned about the ICE re-warm-up, I can guarantee that you will get lousy mileage after your car explodes from ignited gasoline vapor.​

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