How is A/C consumption in Prius?

you're filling up way too soon, there's plenny of gas left.

 

If it was the AC, it would show up in the MPG.

I'll guess you are filling up ~ 10 gallons each time. Since your meter reads 51 mpg and we know it is about 5% optimistic,
you can expect
10 * 51 * 0.95 = 485 miles between fill-ups.

I don't know why the car calculates 540 miles till empty right after a fill-up. Perhaps it thinks you are going to use 11 of the 11.9 gallons available ?

 

9.4 gallons * 51 mpg/gallon * 0.95 fudge-factor-for-inaccurate-gauge =
455.43 miles.

Sound about right ? Just realize that ~ 2.5 gallons are unused when you fill-up. So if pressed, you can easily drive another 100 miles.

 

yup

 

I think you should continue to do what you do, running one of these things out of gas can be a pain, I think that's why the guage and the computer turn that flashing bar on with a couple of gallons left in the tank.

 

it's interesting that it keeps resetting to 540 when you fill up, but ends up close to zero when the light comes on. i thought the top number (which is an estimate based on your mpg history i think) would start coming down with each tankfull so you would have a more realitic idea of how far you can go. it sounds like it starts out taking the safety allowance into consideration, but at some point, adjusts so you're near zero when the light comes on.

 

Yep, that part of OP's story is inconsistent with my experience driving both the CTh200 and a Prius vagon. So far as I know, these two cars have the same innards as the G3 Prius.

OP did not say it is particularly important to him to drive more miles on a tank; I think he was just wondering at the discrepancy. There is not doubt though that a substantial reserve of fuel is still in the tank when the meter says '0 miles left.' Since most of my tanks this time of year end up about 52 - 54 mpg on the meter, my trip meter usually tells me I have low 500 miles left after fill-up. In pursuit of cheaper fuel, I not infrequently run past the '0 miles left' warning at least 25 miles and up to 50 miles without a concern.

 

i do the same. and my dte starts around 510 and when the bar blinks, it is around 10. and i go about 500+- on 8.0 gallons, so it's pretty accurate.

 

Toyota don't want you to empty the tank which is what you would have to do to get the mileage from a full tank the Prius calculates.

 

That makes no sense, and does not match what I see every tank.

 

it's okay, but it's never a good idea.

 

I do.

My second tank I went 534 miles with a indicated MPG of 55.6. (Mine is optimistic by 2.6mpg)

I was only able to add 10.17 gallons to a 11.9 gallon fuel tank leaving me to believe I had 1.73 gallons of "reserve".

Travis

 

I commute to and from downtown LA and always drive 40-60 miles after it says 0 miles left. I normally fill about 10.4 gal and have at least 600 miles per tank.