PRIUS is starting to piss me off

[newlifein5]

what'z up all.

just got back from another long trip again.

this time another wierd thing happen and was hoping someone can share some insight.

filled up full tank - got 513 miles out of a 9.5 gallon fill up.
filled up full tank on the way home. got 379 miles out of a 9.5 gallon fill up.

WHAT THE F... JUST HAPPENED? I LOST ABOUT 130 MILES.

SAME ROAD N ROUTE
SAME DRIVING TECHNIQUE
SAME CAR N DRIVER
SAME GRADE OF GAS - REGULAR 87

only difference is a 10 degree in outside temp drop.
and pumped gas 2nd time at a different gas station. which both were shell.
neither difference should have made a 130 mile lost.

EACH TIME I DRIVE THIS PRIUS I STARTS TO HATE IT MORE AND MORE

[Stev0]

<div class='quotetop'>QUOTE(newlifein5 @ May 7 2007, 12:31 PM) [snapback]436937[/snapback]</div>

only difference is a 10 degree in outside temp drop.
[/b]

That's your answer. Last month was in the 40s here, and I got about 41 MPG on a two-hour-each-way run. The month before was in the 30s, and I got about 38 MPG on the exact same route. Yesterday was in the 50s and I got 45 MPG on the exact same route. As the temperature drops, so does the MPG.

[Rxmxsh]

Well the first thing that comes to mind would be the elevation that you're traveling. Uphill vs. downhill scenario.... headed downhill one way, uphill the other...

[efusco]

You said it was a long trip...so the only difference wasn't the outside temp, it was the direction of travel (with wind one way against the other?), elevation change (down hill outgoing and uphill coming home?).
What was the mpg on the display each time?
Using calculated mpg based upon the amount of fuel the car takes is frought with error.
The MFD is a much better tank to tank assesment of your FE.
Also, did you check your tire pressure?
Could you have a low tire?
Were you carrying any extra weight in the car coming home?
Were the roads wet?
Was there more traffic?
And, finally, what would make you 'hate' the car just b/c you're experiencing differences in FE that you don't yet understand? It takes time, there are a ton of variables and, esp. on freeway travel, those variables can have dramatic impacts on FE...or relatively so. Be patient young Padiwan....all will be clear to you soon enough.

[dogfriend]

<div class='quotetop'>QUOTE(newlifein5 @ May 7 2007, 10:31 AM) [snapback]436937[/snapback]</div>

EACH TIME I DRIVE THIS PRIUS I STARTS TO HATE IT MORE AND MORE
[/b]

Don't be a hater. 379 mi on 9.5 gal is 39.9 mpg. Name some other cars that get 39.9 mpg combined.

I think that what happened is that the fills were inconsistant because of the differences in how the pump shut off. It has happened to me a couple of times. Averaging the mpg from 3 or 4 fills gives me about the same as the MFD mpg even though some of the individual fills are way off.

[jtmhog]

<div class='quotetop'>QUOTE(Rxmxsh @ May 7 2007, 01:35 PM) [snapback]436945[/snapback]</div>

Well the first thing that comes to mind would be the elevation that you're traveling. Uphill vs. downhill scenario.... headed downhill one way, uphill the other...
[/b]

Do not calculate the mileage--use the screen. There must be 100 threads complaining about the variable size of the bladder inside the gas tank. The tank size depends on the time of the day, temperatue, moon position, greek symbol, sun spots, etc.........

[San_Carlos_Jeff]

You didn't say what the indicated MPG was on each tank. The fuel bladder in this car is notorious for giving inconsistent fills when fueling up. You probably had less gas on the second tank, and that combined with the cooler temps reduced your range.

This is the first car I've ever owned where I've given up calculating MPG at each fill-up. I did that for a couple months and the inconsistent fills would give me numbers all over the place. Instead I'm keeping track of all gas used and using that to figure out my overall avg. MPG (it's 45.3 btw).

[MegansPrius]

<div class='quotetop'>QUOTE(newlifein5 @ May 7 2007, 12:31 PM) [snapback]436937[/snapback]</div>

what'z up all.

just got back from another long trip again.

this time another wierd thing happen and was hoping someone can share some insight.

filled up full tank - got 513 miles out of a 9.5 gallon fill up.
filled up full tank on the way home. got 379 miles out of a 9.5 gallon fill up.

WHAT THE F... JUST HAPPENED? I LOST ABOUT 130 MILES.

SAME ROAD N ROUTE
SAME DRIVING TECHNIQUE
SAME CAR N DRIVER
SAME GRADE OF GAS - REGULAR 87

only difference is a 10 degree in outside temp drop.
and pumped gas 2nd time at a different gas station. which both were shell.
neither difference should have made a 130 mile lost.

EACH TIME I DRIVE THIS PRIUS I STARTS TO HATE IT MORE AND MORE
[/b]

As others have told you before, calculating MPG in the Prius off the amount you put in the tank won't give you accurate numbers. The gas tank varies in size due to temperature. If you choose to ignore that info and then get "frustated" with your mileage, the error lies in you, not the car.

If you want to understand why and see what the gas bladder looks like, try reading this thread:
http://priuschat.com/index.php?s=&show...st&p=419197

[F8L]

Some people just like to bi$%^ and complain......

[dragonfly]

<div class='quotetop'>QUOTE(newlifein5 @ May 7 2007, 10:31 AM) [snapback]436937[/snapback]</div>

EACH TIME I DRIVE THIS PRIUS I STARTS TO HATE IT MORE AND MORE
[/b]

Then you should definitely sell it. No car is worth this amount of frustration.

What will you replace it with?