Q about the gas tank

How far did you drive on gas (HV)? With listed 55 mpg, it will use half of tank in ~300 miles (~480 km).

 

It’s because of what I would call the funnel effect. The liquid level drops faster as the walls of the container get closer together as the liquid drains. So I think it’s because of the shape of the gas tank. Just a quick disclaimer—I’ve been wrong more than once

 

Assuming you did not charge during the trip, you mean, the first 500 km on the way, you lost half of tank, but on next 500km on your way back, you lost more than half of tank?

 

I am not sure if the half point in the gas gauge on PRIME is really half empty gas tank. I know when gas gauge is showing completely empty (meaning no bar lit), there is still more than one gallon of gas left in the tank. Rate of decrease may not have changed after half point, but it may give you an impression it decreased more rapidly if the half point is really not at the middle of gauge.

 

I’ve always observed this with my cars—for example I might get 200 miles from my Audi’s first half of a tank, and then 145 miles out of the second half. But I think it’s correct to say that the second half is not measured like the first, as stated above.

 

Yes, I have seen the same behaviour with some of my other cars as well. My point is when gas gauge is pointing empty, it is often not completely empty.

 

See also yesterday's fuel gauge thread: Is the fuel gauge to be trusted? | PriusChat

 

Yap, your comment explains it all.

 

Also a full tank is not all gas....

 

Both the GII and GIII do this. I'd say it's "normal".

 

the pip has 8 bars and each represents a gallon. i'm surprised they were not able to accomplish this on the prime.

 

PRIME also have 8 bars, but 1 bar is further divided into half bar making 16 increments. I have not done a long HV drive in a while to see how the rate of gas use changes (or not change) after a half point on my car. If 1 full bar = 1 gallon, then there must be 3.4 gallons of gas not shown in the gauge, presumably above full mark and below empty.

 

perhaps a bar represents more than a gallon, since the prime tank is larger than pip. idk. pip has a bout 2 gallons left when the last bar starts flashing.

 

The gas gauge will tend to hold on full inordinately long, before it starts dropping. It's really hard to judge your fuel consumption based on that gauge. Also, maybe your speed for the second half of the tank was higher, and/or headwinds, and/or grade change.

Just assume there is a plausible explanation?

 

Since I am doing long distance driving for the past few days, so I have noticed that the first 100 miles on HV, you has gauge will not move at all. After that first 100 miles gauge moves pretty fast but at uniform speed. Every 120 HV miles seems to be equal to 1.5 bars on gas gauge.

 

AND, if you do as I do, that is, fill the tank until I see fuel in the filler tube, you get an extra 200 km range! Well, maybe 100.
Oh, and no, I won't harm the car doing this because I actually USE my brain when doing so.