fuel mileage drop while not moving

What was your MPG when you returned to the garage ???

 

I would wager that you had clocked very little miles on that tank of gas which is why you saw such a big swing in a short amount of time.

It makes perfect sense that an idling car is going to use fuel and thus drop your MPG average since you used fuel and were not traveling.

 

I have a much bigger problem. Okay,I live in Vermont and it is cold... but I am only getting 36 mpg. surely that is not usual. My dealer says it is, but drove a rental Prius II a few years ago and got an avg. 46 mpg. This is a 2010 and I am very disappointed. IS this normal or should I press my dealer about it. (I would never buy another car from this dealer any way)

 

Texas Bob: What you are describing is normal. With only 90 miles on the tank, the swings are more frequent. You won't see that when there are 2 dashes left on the fuel gauge.

 

36mpg is rather low but don't ring any alarms yet. My last two full tanks were 38mpg, hand calculated, and I know how to drive the car. I see that you are new to PC. If you haven't, please run a search about factors that influence mpg. Short trips (under 15min) in this weather will kill the mpg. Do you have a block heater? What are your tire pressures? Driving style?

 

please answer the questionnaire

If it was a few years ago, you had to have driven a 2nd gen vs. the 3rd gen you have now. Please answer the questions at http://priuschat.com/forums/gen-iii...-answer-these-questions-esp-if-youre-new.html.

If the few years ago was in warmer weather vs. the cold weather now, that's responsible for a significant portion of lower mileage. We also have no idea what the commute and trip lengths were like when you had a rental vs. now.

 

Did it ever go back to what it was? Also is 54-56 mpg usually what you get on you car?

 

The only thing that surprises me is the drop from 56.0 to 55.8 before the ICE started. I'm not sure how to explain that. The rest is all as expected if you have very few miles since you last reset.

 

You can see the mpg value drop (and the average mph value too) while sitting at a red light, all quite explainable if the ICE is running. As to the mpg value dropping before the ICE starts, remember that the mpg value is updated at a regular interval. Probably it was about to update to a lower value just as you drove into the garage and turned the car off, so the drop occurred just after turning it on the next day.

 

If your numbers (and my math) are accurrate:

90 miles since fill up @ 56 MPG = 1,234 teaspoons of gasoline

90 miles since fill up @ 54 MPG = 1,280 teaspoons of gasoline

Between the last time the vehicle calculated the MPG before you shut off the vehicle and when you reached the end of the street, the ICE burned through approximately 46 teaspoons of fuel.

About 5 teaspoons were used before the vehicle was turned off.
About 18 teaspoons were used, while you sat still and waited for the door to close, to warm up the ICE.
About 23 teaspoons were used, while you were moving 200 feet to the end of the street, both to warm up the ICE and to propel the vehicle.

If the vehicle had 450 miles on it instead of 90 and went through the exact same transitions, you would have seen the following instead:

450 miles @ 6171 tsp fuel = 56 MPG
5 tsp between last calculation and shutoff = 6176 tsp = 55.96 MPG (rounds to 56 still?)
18 tsp used while sitting still = 6195 tsp = 55.79 MPG (rounds to 55.8?)
23 tsp to drive 200 feet = 6218 tsp = 55.58 MPG (rounds to 55.6?)

 

Rest assured that you are getting far better mileage idling in the Prius than any other car!

 

You need to get a hobby.

 

It's our cold weather. Are you running snow tires? That hurts as well. I'm just under 40mpg average on my first 3 tanks, though I can resent my trip odo once fully warmed up and see 50 easily.

Our extreme cold warmups just kill the overall average. I just posted this in another thread....

 

mulliganforge802: Greetings and :welcome: to Priuschat!
Your G3 is normal. I can save you some gas and time by telling you not go to your dealer to complain about your mileage.

There's a bit of a learning curve for this car, but it's not daunting, and depending on your mileage desires versus your driving style , you can easily get the 50 or so MPG that your car is rated to provide---even in the frozen north, during the winter months, and using E10 gas.
Some quick tips:
* Ignore the goofy digital display for short trips.
* Make sure your car's tires are 'properly' inflated. Depending on how anal you are about mileages and tires...'proper' for you may be 40/42.
* Limit sudden braking and acceleration. Keep the HSI display mostly in the ECO range while driving.
* Don't warm your car up in the driveway (or garage) and keep your heater settings closer to 65 than 85.


If you do these things and tabulate your mileages by the tank, instead of how you're doing on the short trips to Starbucks---I think you'll find that you're really closer to 45 than 35 MPG.

I'm getting 58, with 'properly' inflated tires, driving like a normal person, and without drafting, grill blocking, or (much) pulse and gliding. (current tank @ 300 miles is 58.2--42MPH average)

Like I said earlier...it depends mostly on mileages you want versus driving style you're willing to submit yourself to.

Good Luck!
Read some posts on the forum.