Tank MPG

Careful, Indy!!

I'm not certain where you get the argument that you are "doing better." Sure, you have a higher average speed, but Wayne's FE is still considerably better. Ask him about his commute -- miles, stop lights/signs, traffic -- and then see if you could find a way to better it!

We all yearn for a bit better. I've said more than once: Oh! What I'd Do to get a Longer Daily Commute!

 

700 div by 60 = 11.6 700 tank is easy. 800 is beyond my reach, I'm sure.

 

That's why I made this statement. Lower speed is a BIG factor in high mileage in my opinion, maybe the biggest.

 

Unless, of course, that is the kind of commute someone drives.

 

In engineering we call it 'managing user expectations' and that is why I've tried to focused on the baseline vehicle performance.

Bob Wilson

 

I've been lurking here for several months and have found it to be interesting. I picked up my Gen III July 2nd and have rolled up 4500 miles so far. I just filled up this afternoon with 589 miles using 9 gallons. The display reads 69.2mpg's and I calculate at 65.4. I've seen a 5.5% gap on each fill. But who's complaining.

This is a mix of all kinds of driving where I take it easy and some times not so easy. I love to hear the squeal of the tires now and then. I've never got below 58mpg's.

 

That's interesting. Most people see the 5% the other way around.

Tom

 

waaaaaaaaaaaaaaaaait just a minute here....I've been assuming that because I've only been able to put 9.5 gallons in, that the "empty" indicator was firing early and that I still had ~2 gallons in the tank.

You're telling me that it's the TOP of the tank that is empty when I "fill" it to the first click off, even when going at a low flow rate??? :shocked:Why does the gauge read full then? (as a practical matter, if I were designing it, I'd want it to err on the side of the user having MORE fuel than they think they have...but that's just me

Ms. Glass Half-Full :tea:

 

What's the point of posting photos of the MFD display? The G3 MFD is so far off that what they should really be taking pictures of is their manual mpg calculations.

 

I wonder how much the extended warranty would be.

 

you remember how to do this ... RIGHT?

top off you gas tank.... to the rim or until you can't get another drop in the tank. Don't spill a drop

Take the mileage down or write the mileage on the ODO.
Do your thing.. drive drive and drive til the refuel light comes on.
Top off you gas tank to the rim or to the point you can't get another drop in the tank

How many gallons did you take to fill the tank?

Then do the math. miles traveled divided by the gallons used. Well ah.... MPG

PS:
this first click or shut off is not the true top off. I can get a gallon and a half more in the tank after the first click off. You need two absolute top offs to get the real MPG. On my CR-V the first click off is very close to the absolute top off.

 

fireing early is good. Gives you 100 mile to get fuel

 

I believe I have put at least two gallons more than the first click, Do so at your own peril of course. My personal observation of other cars that I have removed the tanks from is that there is a bump on top of the tank where the vent is connected, and your not filling fuel up in that bump, the shape of the tank prevents that. I would assume the Prius is the same way. But I do believe it's possible to damage the system by filling the tank completely full of cool fuel and allowing it to sit in the sun and expand. I see aircraft venting fuel on the ground all of the time from this.
I have seen documentation that GM intentionally has their fuel indicating systems calibrated so that by the time the gage is indicating 1/2 much more than 1/2 of the fuel has been used. They do this because most people refuel with a lot of indicated fuel remaining and therefore they are not getting as much use of the tank as they could. I assume this may be an industry standard? All vehicles that I have exhibit this.
I know a person that is convinced that her Tahoe gets worse mileage in the last half of the tank, so in order to get better mileage she refuels before the gage indicates 1/2. You can't make that up, it's too stupid, but she is convinced.

 

The air gap in the top of the tank is called ullage. It's designed into the tank to allow for thermal expansion.

 

? I think most of us have the similar situation where the MID numbers are about 5% or so higher than the calculated mileage. Right?