Another mpg vs. Pip problem

I'm not sure what the "problem" is. Are you saying you've lost 1 pip after 30 miles or each pip goes away every 30 miles? How is that a "problem"? I've had the considerable variance on how long it takes for the 1st pip to go away, esp. if I refill/top off while it still indicates "full" or is nearly "full".

We call it the "guess gauge" here. Examples of what I would consider a problem are, if you run it down to 1 pip and can't put in much gas (say 5 gallons) or you somehow run out of gas with it indicating some value above empty.

Perhaps http://priuschat.com/forums/other-cars/94001-gas-gauge-says-full-but-thats-not-quite-true-npr.html would give you a little more perspective.

It is possible the inclinometer might need to be reset (http://priuschat.com/forums/gen-ii-prius-main-forum/8123-gas-tank.html#post1073746). However, I'm not convinced yet that there's any problem or that you should muck w/that yet.

 

Yup, pretty much all of us. How much fuel the gas tank holds depends on outside temperature. When it's warm the internal bladder is more flexible so you can squeeze more in, and the opposite is true when it's cold out. I have seen the first pip go as soon as 10 miles after a fillup or as long as 160mi during the peak of summer.

One of the many things I use my scangauge for is as a better gas gauge. It can read the level directly from the tank from 0 to 100% in 2.5% increments. It isn't a perfect solution, either, since that raw readout is not corrected for inclination. But I prefer it to the silly pips.

 

'my pips are disappearing at around 30 miles' sounds like a different issue to me. i would run it by the dealer and see what they think. in the meantime, fill up more frequently so you don't run out of gas. that can be a real humbug.

 

Just go by the electronic mileage and fill up every time the tank gets down to half full.

 

Yeah, that's a good point. This is where the scangauge would be useful to see what the actual sensor is reading. If the pips are way off of what the sensor says (like 3 pips left but the float is reading 65%) then it might well be that the inclinometer needs to be recalibrated.

 

The OP needs to clarify what the issue is (if any). I'm not clear if he saying that his 1st pip goes after 30 miles or if they ALL disappear after 30 miles.

 

This is what mine is usually like

1st pip gone @ 90 miles
2nd pip gone @ 120 miles
3rd pip gone @ 150 miles
4th pip gone @ 180 miles
5th pip gone @ 220 miles
6th pip gone @ 260 miles
7th pip gone @ 310 miles
8th pip gone @ 360 miles
9th pip gone @ 410 miles
flashing @ 440 miles

 

Here's what mine looks like (approximately). Note there's no bladder and the distance is in km.

1st pip drops @ 245 km
2nd @ 330 km
3rd @ 415 km
4th @ 500 km
5th @ 585 km
6th @ 670 km
7th @ 755 km
8th @ 840 km
9th @ 930 km
Flashing @ 980 km

Refill approx 42 Liters

 

so fifth pip = 150 miles driven?

 

i think you're getting it. but try to understand, the pips don't have anything to do with your mileage. it's the tank bladder, the outside temperature, the fuel pump you're using and your particular cars idiosynchrosies that are affecting your pips. ignore them and concentrate on your manual math calculations as you mention above.

 

How are you determining that you're getting "30 mpg"?

Yes. You need to do that. You also need to average about the values over many tanks (may as well do it for the MFD values as well). You will frequently find considerable variance between the two for a specific tank but will find that when you average them, they're very close.

Example: MFD could read 45 mpg yet your manual tank calculation might show only 40 mpg. Then, on the next tank, it could be the reverse.

Exactly!

 

^A whole post from Andrew without one hyperlink. Haha! :thumb:

Yeah whatever they said.

 

well done.

 

Just don't rely on the odometer when it starts to turn cold again. Our fuel tanks are less flexible in cold weather, and hold less fuel as a result. You should still fill up when the gauge reads low.