I ran out of gas @ 460 miles getting 46.5 mpg

This is the case with my '02 Prius as well. I have been tracking since I bought the car and more often than not the MFD (the display) would be overly optimistic about my MPG.

See the attached graph for all my fill-ups. There is on 51MPG which might be a mistake of some sort since all others are in the 45MPG range. I'm in the Washington DC area and the increase in fuel efficiency for the last few fill-ups is due to the fact I started to garage the car (the ambient temperature overnight there is 50-60F instead of 30-40F). For the last fill-up I also covered the front and I feel it helps, but it remains to be seen after a few more fill-ups in colder weather if it really helps much...

I do reset the MFD at each fill-up.

 

probably already said, but you do have an 11 gallon tank and the issue is that it was not completely filled the last time. it is difficult and VERY UNWISE to try to top off.

when last bar blinks you have about 12% tank left. that is about 1½ gallons...i would assume one gallon if i were u, especially in winter (much more pleasant to walk to gas station on warm sunny day)

P.S. now if you were to refill your tank and get 11.9 gallons in, then you should be upset... but im betting you put in around 10 gallons right?

 

To djhnd & other newbies:

What really counts here is NOT how much gas you THINK you have left, but how much gas you KNOW you ACTUALLY ADDED at your last fill-up (because of that bladder). I've had occasion to have 2 fill-ups at about the same temperature & the 1st pip disappeared around 180 miles (from the reset) in one tank, but on the other tank that 1st pip disappeared after only around 90 miles (from the reset). So if you consider about 45 MPG (which was probably very close for that temperature), then there was about a 2 gallon difference (shortage) in the later fill-up (maybe a different station or a different pump at the same station---I don't remember). Different pump nozzles have different shut-off sensitivities & it may NOT be the splashback of the liquid gas that causes the shut-off, but could be the back pressure of only the vapors (since our bladder tanks also have a very tight seal in the filler neck that sometimes makes it difficult to insert or retract the pump nozzle).

I always get my gas at 2 pips left, very rarely at one solid pip, & NEVER would let it go as low as the blink'g pip. In the summer I generally get 400 to 420 miles between fill-ups, but in the winter it drops down to around 350 to 375 miles between each fill'g. I know there's a 700 mile club over at PriusOnLine (DanMan32 in Florida has gotten a few of those tanks) & some hypermiler has gotten an 800 mile tank, but for many of the rest of us, we may never see a 600 mile tank or even a 500 mile one. I've never been able to squeeze in more than 9.5 gallons, but does that mean that I still had 2.4 gallons left in that tank? I DON'T THINK SO, & I'm NOT willing to push my luck to find out either.

Also, I have a 2005 model & it automatically resets the MPG average on the screen if I add at least 3 gallons of gas (or is it a 2 gallon minimum addition for the MPG to reset or the pip display to show any chg?). I believe the 2004 also shows only the PRESENT tank's MPG just like the 2005 does. Ideally, you want to know how many gallons you TAKE ON & that tank's PRESENT MPG (NOT LIFETIME MPG) to calculate how far you can safely go without running out. Some people are so anal on LIFETIME MPG (like I believe the Classic 2001-2003 had) that Toyota dropped the auto-reset of the 2004 & 2005 and went back to the LIFETIME MPG for the 2006 & newer models.

This LIFETIME MPG can really be mislead'g if you're count'g on it to calculate how far you can safely go on a particular tank. Over many thousands of miles you may not see much of a variation in the LIFETIME read'g even if you've had the car & defroster running for a long time to clear ice & snow from a bad storm. Last winter I had my car running for at least a half hour to clear ice & snow, so without it moving but still consum'g gas, my (AUTO-RESET) MPG display took a 10 MPG hit (for that tank only), so I wouldn't get as far any more on THAT tank. But you wouldn't SEE that kind of hit on a LIFETIME MPG display, yet you still wouldn't get as far on THAT tank since you did still burn that extra gas.

So I recommend that everybody with the 2006 & newer Prius ALWAYS do your own MPG reset when you fill up [& remember how much gas you took on (NOT how much you THINK you have left) or keep THAT receipt handy] to help you calculate your safe travel limit using you CURRENT MPG read'g from THAT tank only.

Ken (in Bolton, Ct)

 

Use the force Luke, use the force.
In other words the fuel gauge is your friend, fill at 2 bars.
Anyone here ever run out with 2 bars of your fuel gauge lit?

Who here believes any car has no petrol in the tank when the engine cuts out because there isn't enough in the tank for the pickup to be submerged?

In boating there is a rule, 1/3 out 1/3 back and 1/3 in reserve. 1/3 of a tank is a little over 3 bars so if you get down to 2 bars you need to top up, you are in reserve.

 

To prove the point of the bladder, I didn't see anyone asking the original poster if he managed to pump in 11.9 gallons when he refilled. Only if that was the case would his original math of 460/11.9 hold true.....

-MKL

 

Our sailboat holds 37 gallons of diesel fuel, which is enough for more than three continuous days of motoring at full throttle. Even though we use less than one tank a year, I start to feel nervous when the level is down five gallons (32 gallons remaining). You never know when you might need to ride out that three day storm without your sails or mast.

Tom

 

for those of you that have CANVIEW, dont read this post.

if you dont... CANVIEW gives tank volume in percent. now it only does it in 2½% increments. so you will see 100, 97, 95, 92, 90% etc...

so, i decided to track when that last blinking bar started since it did seem to have a pretty wide variation as to how much gas was left.

in the 13 tanks i tracked, the blinking bar came on right at 12% (although it read 12, its actually 12½% but there was 3 times where it flipped to 10% within 10 miles suggesting that tank was actually closer to 11% by figuring each percentage point to be worth about 6 miles which approximates 55 mpg right? all calculations were done in summertime)

anyways... 12% is about 1½ gallons... so if you are getting 46~mpg, have gone 70 miles on that last bar... well, not saying you are foolish, reckless or ... well, just not saying...

 

I'm convinced there are two types of Prius drivers:

• Those who never run out of gas
• Idiots

No, seriously. There are gas stations EVERYWHERE. You don't have to wait until one flashing pip to fill up. Even if you do, once the display says "add fuel", DO IT!

This isn't rocket science. The car tells you to "add fuel". You don't do it. The car runs out of fuel.

Whose fault is this?

 

Does your CANview tell you how much fuel is in the tank below the fuel pickup? When you run out of fuel like as if the car has no fuel gauge, there is still some fuel in the tank which the pickup is above. This is done deliberately to prevent any small amount of water that finds its way into the tank from finding its way to block the filter or injectors.

 

Good retort. However. I think the general consensus is, that if you had read the hundreds of posts about this exact issue (and believed them), you never would have started just-one-more-thread-about-inaccurate-gas-readings. You would have educated yourself about the problem before letting the problem happen to you.

 

My dog thanks you.

Get a thicker skin. Yea we all piled on, but come on lighten up. The best thing to do is to give it right back to us.

 

It's an easy mistake to make. Let he who is without sin post the first ill-humored reply.

 

djhnd:

I simply lost count of how many good folks you find here at PriusChat, who will go out of their way to be very helpful and balanced in the information and support they provide.

With that said, every forum has its own set of blunted and immature know-it-alls. Please do keep the names and don't let the few get to you and keep you from the awesome value contained in this forum.


Cheers;

MSantos

 

The snarkiness of replies is often directly proportional to the vehemence of the original post. If an original post says something like: "I don't understand how I could have run out of gas..." the replies will usually be fairly gentle. If, on the other hand, a thread starts out with bold letters stating that the Prius is all messed up and the design must have been done by chimpanzees, but the assertion turns out to be groundless, then you can expect a few more fireworks in the replies. You want to tread lightly unless you are very, very sure, and even then, I still like to tread lightly.

Tom

 

That's how I viewed the replies in this thread. Due to the brashness of the first post the rest of the replies were bound to be equal in tone.

 

sorry to hear about your predicament. hope you learned something abou the prius. on a side note, i'm currently trying to push my car to use at least 10 gallons because shell is doing a promo for a b1g1 free lift ticket deal right now. i've noticed that in winter it's really hard to get a 10 gal fill up. i usually end up around 8.5 to 9 gallons. i guess i'll carry around an extra gallon of gas when i get down to that last bar, lest i post here and get berated by the friendly people here at priuschat. just so you know, just cause some or most here lean more towards the left doesn't mean they are more friendly.

 

Why not put 9 in the tank, and one in the can? That's a 10 gallon purchase and you can get your lift ticket.

 

i got a 2 gal. canister i need to fill up for the mower when spring comes around. great idea, thx chalk one up for 1 helpful priuschat poster

 

I am sorry but I laughed at your post. If you only knew how many times we see this on the forum and are coached about it.

I am sorry you ran out of gas. The Prius has a weird guess guage.

The only reason I think I did not run out of gas or overfill the gas tank, is because I joined this forum before I bought the car.

That said I start sweating when I go past that 2nd pip. I would faint on a blinking pip.

I would DIE of embarrassment on the side of the rode for running out of gas in a PRIUS. We already take a lot of heat. I got called an aggressive Prius driver the other day.