2010 "Miles to Empty" Accuracy

I sort of think of this the same way I look at the milk in the fridge. With two daughters a gallon of milk may last 2 days, a week, or anything in between. If we have less than a half gallon and it is convenient I'll pick up another. With gas anytime I have 4 or less pips I'll stop if it is convenient and cheep. Sure I may have an extra stop or two at the gas station every few months, but it is never a problem. Same goes for the milk - I avoid the hissy-fits in the morning - either for a daughter that needs milk for cereal or a wife needing it for coffee.

 

Yes, at least two:
- It can damage the fuel tank management sensors and valves. This can shut down the car and cost hundreds to fix. Search the site for posts by Prius tech Galaxee for some sob stories.
- It saturates the vapor recovery canister, which increases air pollution. Did we pay extra for a Prius to increase air pollution?

Topping-off is really oldschool. Don't do it.

 

I have driven until the "miles until empty" reads 0 miles and the last pip on the gas gauge blinks a few times. If I fill it at about that point it will take about 10 gallons.

Although I don't make a habit of it I think I can safely go at least 50 miles after it indicates 0 miles to go.

After Bob Wilson's tests I don't want to run out of gas but if I do the important thing is to pull over and shut the car down as soon as possible. As to the other things, I have violated all those "don't run low on fuel" rules a time or two and nothing bad has happened because of it, at least not yet.

 

I just traded in an '02 Sonata that I'd topped off too many times. The charcoal canister that absorbs the gas fumes was ruined (a $600+ fix) and I was at the point of it taking about 15 minutes to put about 10 gallons of gas in. The pump would shut off after .6 gal. and I would have to wait at least 15 more sec. to put in another .6 gal. This seriously cured me of ever topping off again.

 

In most cars, there are two things you do NOT want to do. Trying to put TOO MUCH gas in it will cause flooding of the evap system from overflow, damaging the charcoal canister (very expensive part for most cars).

Letting the gas run TOO LOW may cause two problems. The fact that you may have excess crud accumulated suck into the pump (mentioned previously). More importantly it can burn out/shorten the life of your fuel pump (very expensive job in most cars). Most fuel pumps depend on the fuel as a "coolant" to draw heat away. No, it's not THAT hot, but hot enough that if the pump runs while dry, it can damage the bearing(s) and/or impeller either permanently, or enough to shorten the overall life of the pump.

 

I noticed the DTE drops quickly as it approaches 0. I was driving home one evening, with the last pip flashing- it said 15 miles to empty. About 5 miles later it hit 0. Fortunately, after it hit 0, I was able to drive 5 miles back to the gas station the next morning.

 

The several times I tried it and watched DTE, it didn't seem to count all the way down to zero. Somewhere between 5 and 10, it tended to snap to zero.

 

I have had the same experience the couple of times i went low

 

just filled up my car and I had 80 miles to empty indicated. went a little over 450 miles (2 lines) I put 8.35 gallons and my tank is supposed to be 11.9 capacity.
Since I traveled over 450 miles on 8.35 gallons, I would think I would be able to get at least 175 miles on 3.55 gallons left.

 

Hi patsparks, I've only had my prius 2010 since july 2010. I live in country Vic and run my daughter to elite soccer training in Melbourne 4 times a week. round trip of approx 400k. about to clock up 80,000ks. have learned to ignore the bip and flashing bar. I can safely run another 160ks. most fill-up I've had is 42 ltrs.

i generally average about 4.8l/100ks. best is 4.2.

 

45 L tank, right?

I'm comfortable running down to 0 km remaining on the Distance-to-Empty indicator. When I do that and fill up shortly therafter, it's almost always 36 L that I'm putting in. That's 9 L remaining in the tank...

4.5 L/100 km with 9 L equals another 200 km before I run out.

-Iain

 

All PIPs are not created equal. Here's the data for the 2010:

View attachment 30965

I got the liter info from the repair manual, then did the conversion to gallons. The data is for when the PIPs normally come ON, so I won't say for certain if the ranges hold for when the PIPs go OFF.

Personally, I'm not convinced that waiting until the last pip starts flashing before refueling has any real, lasting value. I usually fill up around 2-3 pips and go my merry way. Miles Per Gallon is more important to me than Miles Per Tank.

(BTW, I think the mods should consolidate all of the fuel tank/gauge/pip threads, or make it a sticky. I just posted the above chart on the Gen II forum, where there are multiple fuel threads, just as there are here on the Gen III forums.)

 

I have been doing experiments on/off with the DTE mileage I found that always starts blinking between 20 to 22 miles to empty and the further I have got after "0"'miles DTE is 40 miles before chickened out. I always drive almost to "0" and pump 9.7 gallons of fuel! so there is like 2 gallons left on reserve always consistent!
hope this info helps

 

+1

My results have been about the same, although I have gotten as low as 18 miles DTE at the start of blinking. Driving at a steady speed in a straight line lets you get a bit further before the blinking starts. I have also had it start blinking at somethng over 30 miles when turning on a steep hill. Usually I am within a mile or 2 of 20 miles when it starts blinking.

My fill-up at 0 miles DTE is usually very close to 9.7 gallons

 

I always set my second trip when the blinking comes on. knowing you have 2+ gal, I run it past 70 miles, then start thinking about getting gas at some point.

I've pumped 11.8 once (120 miles on blink - but was coasting into the station) - at 70 past blink, you're looking at typically 10.5 gal...

 

Tideland I just ran mine till the display read 0 to Empty the other day and there were 8 litres in the tank...so my experience bears out your results, I figure I could have gone another 100Km easy.

 

I didn't read every post but there are some mechanics that claim you could prematurely kill your fuel pump by running your fuel too low. The gas suppsedly keeps the pump cool and can help make it last longer. I heard it is recommended that drivers should fill up no lower than 1/4 tank.