PRIUS is starting to piss me off

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

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.

 

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...

 

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

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.

 

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

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......... :lol:

 

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).

 

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

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

 

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

 

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

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

What will you replace it with?

 

well I had a similar thing happen yesterday driving 2 hours on a trip. The weather down was great, I averaged 53mpg it was in the 60's
Leaving at night however, it was raining and snowing and wow did the viability and weather suck. the temp drooped down to 34 to 32 and obviously with the heat on and the resistance from the slush on the road the mileage dropped to an over all 46mpg.

Its ok, once it stopped raining and I was on dry pavement I made my mileage up by slowing down and was able to get the over all back up to 51mpg.

sometimes the climate control can have a big impact. did you maybe have the heater on and not realize it? AC?


Also, just because two gas stations have the same gas does not always mean its the same gas quality. gas expands in heat, did you fill up in the morning or afternoon?

Also did you fill it too the click or did you overfill sometimes? under fill? Was the pump the same type of pump? some pumps are older.

Parking break on? that always has a negative effect on mileage. also cargo and dont forget
WIND! a cross wind can screw you up pretty bad too. windy days are the worst unless you get a tail wind.

 

In my commute from Oxnard to Northrdige, I get about 48 MPG.
The return trip, I get about 52 MPG. The 4 MPG difference is small but pretty consistant, and the only real difference in my case is the terrain; I think the trip must go uphill from home to Northridge. Speeds are the same, about 65 MPG, and temperature is (if anything) a little cooler on the return, since I tend to return in evening, after sunset.

 

and check the stickers on the gas pumps -
sometimes there is alcohol mixed in (gasahol) ; sometimes there is not. that has an impact on mileage.

as mentioned above, the fuel tank is not fixed capacity - it is variable in size. that is just the way its built; we need to get used to that, and its effects.

look at your computed mileage over say 10 tanks to get a better overall idea ot whats happening.

 

<div class='quotetop'>QUOTE(oxnardprof @ May 7 2007, 03:08 PM) [snapback]437120[/snapback]</div>

oxnardprof + Northridge = CSUN ?

 

<div class='quotetop'>QUOTE(MegansPrius @ May 7 2007, 11:52 AM) [snapback]436987[/snapback]</div>

Due to the well known inconsistency in filling the tank, choosing to calculate mileage from only one tank of gas WILL lead to frustration.

Doing so makes as much sense as trying to calculate the average monthly temperature with just one temperature reading per day.

More date points are needed.

Calculations using ten fill-ups will give you a tenfold better chance of arriving at a commonsensical answer to your question.

Otherwise, just use the MDF mileage for day to day indications. The MDF calculations don't care if you filled the tank with five gallons or fifteen.

 

We all have variances in our milage depending on the wind, temperature, need to pass people, conditional tank size etc.

Do you like the car?

 

plan on responding to any of these posts?

 

Guess not.

 

Boy I love when people do that.... ::Sarcasm::

 

Maybe he sold it.