out of gas , getting out of safe mode

Answer: fill up at one bar (not flashing bar) before going home if hospital is within five miles. Fill up at two bars if hospital is farther away. Fill up at half tank if worried about getting caught in mass evacuation or blizzard or ...


To each his own I guess, but if I ever buy a used Prius, the top question I would ask is if the previous owner ever ran out of gas. And I would only buy directly from the original owner, not a dealer or a second owner, unless the battery pack has been recently replaced.

 

It depends what kind of jam you are in. Admittedly, you will probably not run out of gas, but I have known a lot of people here who wait until their car is on fumes before refueling; if they got stuck in a jam then, they would be screwed.

If there is a jam on i-10, then HPD or Transtar or whoever gets on it and clears some lanes so traffic can resume. One time however, I got stuck on Memorial Drive, not sure between what and what; it was a mile streth where 2 roads merged onto Memorial, and there were no exits. Took me about 2 hours to go one mile, no kidding. It took that long to move, that with the A/C on low and the radio on, the battery must have been recharged at least 15 times. It was insane. Now keep in mind some people run their tanks almost dry, and thats a very precarious situation.

Well I personally prefer heat over cold, and I spent about 10 years or so living in the 130 degree heat of Saudi Arabia; but in general heat really gets me down, and I can only truly enjoy it with A/C. Therefore, even if its just, say, 72 degrees, I'll have the A/C on set to 68, and the A/C seems to drain the battery in the Prius faster than anything.

I also dress for winter, and usually don't have the heat on in the Prius anyway. Even so, the engine on the Prius runs a LOT more during the winter; what might be a 1 minute warmup in summer turns into a 5 minute or more warmup in winter. And this is Houston winters; as low as 35, but not as bad as some places in this country by far. Its hard to slicky exit the parking lot of my apartment complex in stealth mode when the damned ICE is still running well after I'm ready to go.

I suppose it isn't that inaccurate; but it is screwy. There are countless threads and posts on these forums about the gas gauge.

I've found it to be fairly accurate myself, its just that first pip that leaves massive ambiguity about the fuel reserves.

That said, I still would like to have the bladder removed; I would be willing to sacrifice some air quality to have confidence in my car.

 

Not having run this thing out of gas, I can't be certain what it is going to do, but I would be very disappointed if Toyota didn't have a way of sensing that it wouldn't restart. It should be able to continue spinning the engine just fine above 41 mph without going to engine braking. (It does this already.) But if it is out of gas, a "turn on engine" signal is received, and Toyota has it stuck in a continual restart loop rather than in timeout and just engine spin mode...well that would be utterly brain dead.

This however is a very valid consideration and one that bugs me. Does the Prius recognize it's status or does it go apeshit and make it far worse? I'm tempted to run it out of gas just so that I know what to expect. (Laugh, but it's like during diving training having your air shut off so that you can recognize the condition and react appropriately.)

No, you weren't stupid. If a car did that to me it would go back to the dealer for repair that day, and I would test it down to the flashing pip on the very next tank. That's a DEFECT and one that I would be ready to go into a lemon law fight if they couldn't fix. Doesn't matter to me if they have to replace the tank to do it. Bad tank design is behind the problem, this would give them incentive to resolve it. I would much rather know if the gauge had a problem on the bottom end than not know.

If you didn't draw the battery down to zip indicated there shouldn't be a problem anyway--not that I would intentionally go that low before shutting down. Zero on the display is not zero charge, it is the bottom of the control range. This "danger" that everyone keeps going on about appears to be primarily psychological or applying abuse situations to a simple "out of gas" condition.

Now one could do really stupid things like restarting it several times to use every last bit of charge (folks actually do that from what I've gathered in previous "out of gas threads.") But just gliding it on down or doing what amounts to nothing more than an EV mode move (as is allowed to European Prius) while monitoring the charge, I don't seen any harm. This is not an amperage that should be problematic. Now if some moron is tromping it trying to maintain highway speeds with just the battery...that's just assinine.

I still remember a cartoon about a guy walking back to his car with a gas can and his wife yelling out the window at him, "I managed to get it another few miles using the starter." This is analagous to the sort of abuse that appears to be behind the "for God's sake, never let it run out of gas" paranoia.

 

I wasn't watching the gas gauge closely, but noticed I was at five bars today with 180 miles on the tank, 45.3 mpg for the tank. That's 4 gallons used. So the variability in my tank is on the top end...either that or it has only 8 gallons of capacity full to empty in current weather. If this sort of variability was on the bottom end of the tank, Toyota would be either fixing it or putting in a new tank under warranty.

This bladder tank design sucks.

 

I'm confused, isn't the motor turning over the ICE without fuel the definition of engine breaking?

and yes, I agree, the bladder sucks...

 

No, not really. The Prius rotates the ICE all of the time once the speed of the car gets high enough. It has to do this to keep MG1 for over-speeding. When it does this, it configures the ICE to have as little drag as possible. For engine braking, the ICE is configured for maximum drag.

Tom

 

I missed this one before... Easy, I take the truck. It's faster anyway.

But let's suppose the truck is incapacitated. In all seasons but winter I usually have about 1/2 gallon of unmixed gas in the shed so topping off at home would be an option. No worries.

But let's suppose it is one of those really bad Murphy-esque days, the car is near empty, the truck isn't in running condition, and there is no gas in the shed. Now if I've driven home on a single pip without filling, it means I've already calibrated this tank at least down to the flashing pip so I'm not concerned. (And I intend to test down into that pip somewhat as well so that I have a cushion.) And realizing that my tank has never taken more than 8.9 gallons at 1 pip despite its supposed 11.9 gallon capacity...I don't see any risk.

But let's suppose I get in, proceed a few hundred feet and the ICE cuts out. Well that would certainly slow me down, but the hospital is close, so it won't be much slower than a normal drive. There is a long downhill run for me for the first stretch so I wouldn't have to use any battery (would actually gain from regenning at the bottom). Then there is a turn and a long flat where I've experimented with extended EV glides. The tough part would be the climb up the hill to the hospital. That would be enough to just about finish off the usable charge after the EV glide I suspect.

Let's assume that the battery gives up half way up the hill. I'll have to carry her on my back that last 1/4 mile. We do this sort of thing for amusement sometimes anyway. (I even have both the kids climb on, although I figure I've only got one or two more years left of being able to carry all three of them together.)

 

As it would be if it were trying to start it...

 

Maximum drag configuration for an ICE is different than running or starting configuration. That said, the Prius control system has only a limited amount of control over the valve timing, so they may indeed be the same in the practical case.

Tom

 

pls i am buying 1998 prius I which has been left for long time now it starts but it goes into safety mode and drives at 10mph, anybody knows what is needed to fix this problem at all, pls advise

 

Buying an NHW10 is a risky venture because you probably won't be able to retrieve any diagnostic codes (since it uses a unique Japanese protocol.)

It probably needs new traction battery cells at minimum. But it may need more, who knows.

Another issue is whether you can obtain spare parts, and the cost of same. Unless you like pouring money into a rathole you can probably do better.