My 2018 Prius Three is draining gas FAST

I think you are OK, but 87 is for the octane rating, and does not indicate anything about ethanol contents. Most octane rating 87 is used for Regular gasoline, and most regular gasoline contains some amount of ethanol but less than 15%. So, as long as you were using the pump labeled "Regular", you should have been fine.

 

how much does a gallon of gas cost where you fuel up?

 

Well, we now know you have been putting regular gasoline and not E85. That's good. And the amount of gasoline you have put in the car so far is abnormally high for the distance driven so far. So, we are back to the starting point of your question when you posted this thread. I still do not have a clue as to why your brand new Prius is using so much gas while the car's display is showing on the contrary. I am sorry that I can't offer you a better answer, but at least we are in agreements that there is definitely something wrong with you car. I hope you will find out soon when you take it back to the dealer.

 

Seems like "go see your dealer and find out what is wrong" is the only actual advice this person needs. Any attempt to determine the height, width, and depth of her issue just confuses. It is of course a great idea to know how much and what type of gas you are putting into the vehicle and how many miles you have driven - but that is not any more than common sense...

 

I'm not sure we know that at all.

Our "patient" is blinded by all the fancy displays and what they are trying to tell her......including an erratic fuel gauge.

ALL that is needed is an ACCURATE record of miles driven and fuel used for those miles.
Everything else is just smoke, confusing the picture.

 

For YOU maybe. Be careful here.

 

Question, where is the emergency brake pedal now.

Is it possibly engaged?

 

By your left foot. Only don't use it in an emergency, use it when you park.

 

Wouldn't it be smoking by now?

 

Agreed. Unfortunately, she did not keep ACCURATE record of miles driven and fuel used for each fill-up for the first 427 miles she has driven so far. To be honest, I don't blame her for not keeping ACCURATE records. Most people would not suspect anything wrong with a brand new car just purchased from a dealer. But with amount of money she paid for gasoline purchased and price of gas in her area, we have rough estimate. With those information, at least we have established a "reasonable doubt" that there is something wrong with her brand new Prius which warrant further inquiry.

 

@Salamander_King is right - most people just put fuel in and drive. Congratulations for being aware. I suspect you don't have a problem at all.

You should ignore the first $15.65 fill - that just relates to making it full in the first place. If the tank was empty and you had to put in $55.00 the day you bought it, you can't count that as related to your usage.


is OUTSTANDING.
- is EXCELLENT
- is maybe a bit below what you'd hope for - but 91 degrees you probably had A/C on HIGH - but averages are like that - you'll have a couple of excellents, a couple of "could have done better";

- are all good averages
AND

I don't have that screen, must be on newer Gen4 models - but if the best is 49.2, but with a mean of 55.3 - I don't understand - I'd have though the "BEST" should be higher than the mean? BUT - 55.3 is a fairly good average anyway.

You can keep track of your fuel use easily with the "FUELLY" app - just enter every fill, and it'll sort it out for you. [You can see at the bottom of my post and some other Members, the FUELLY averages.]

A spreadsheet if you want to set it up ...

OR a simple notebook and use a calculator to compute it. - like this (very old one from 40 yrs ago, pre-computer) - the arrow is my calculated MPG.


Columns are 1) kms since last fill, 2) MPG, 3) ODO, 4) cents/litre; 5) TOTAL purchase. [I wish fuel was that price today!!!].

 

Yes, if we assume she had partial tank when she drove off from the dealer and immediately filled up the tank and paid $15.65, then we have better handle on her actual mileage.

Her statement did not say, she filled immediately after she drove off the dealer's lot. She just said the dealer did not fuel the car. So problem is we don't know how many miles out of 427 miles she has driven after she purchased the car but before the first fill-up.

If we assume she did fill-up immediately after the purchase and no miles are put on the car, then two subsequent fill-up are the amount of gas used for 427 miles driven since the purchase. Even with this assumption, $35.67+$21.17 paid for gas at ~$3.50/gal would be 16.24 gallons. If that amount is used for 427 miles of driving, then it is now 26.3mpg which is still far off from what would be expected of brand new Gen4 Prius. Of course, we don't know when she checked odometer and saw 427 might have been sometimes after the third fill-up, so the actual distance driven on 16.24 gallons of gas may have been actually shorter than 427 miles which makes actual mpg even worse than this estimate.

 

my money is on miss calculation.

 

The drill:

1. Note odometer reading when at the gas station filling up. Fill up till the pump first shuts off, call it done.
2. Drive the car on that tank till it's low enough to refill, and fill up the same as in Step 1.
3. Note the odometer reading again, AND the number of gallons you put in.
4. Subtract first odometer reading from second; that is your distance traveled on that tank. Divide the number of gallons into that distance traveled; that is your mpg.

Note, you can forget about the odometer, just use the trip meters to record distance traveled on the tank, BUT the odometer is bullet-proof.

 

Somebody needs to set aside an hour, and read her owner's manual.

Listen to this old man:

- Go get gas! Fill it up until the pump automatically clicks off. Remove nozzle.

- Put Trip-A on the dashboard. (using the steering wheel button on the left side of the wheel.) Trip-A will show up right under the speedometer.

- Zero out Trip-A!

- Start driving! Drive THREE WEEKS as you normally do. Don't try anything fancy, just drive! Forget it's a Hybrid!

- Don't look at anything else but Trip-A! Forget all those other screens! Forget the small daily mileage!

- At the end of THREE WEEKS, take a picture of the little Trip-A display, and post it here.

I bet your MPG for Trip-A will be somewhere between 53 and 57. (which means it will actually probably be 55.)
(bisco will have to be patient for 3 weeks. Longer than that, and he starts getting itchy )

 

Trying to get this solved before it reaches 100 posts?

This about as good as the swamp cooler thread from a couple of years back.