My 2018 Prius Three is draining gas FAST

You win.

 

The way I look at it.... Anything over 30 mpg is great gas mileage. So I'm not too concerned with the mpg on my Prius.

It's a PRIUS, man. Just drive it!

(On second thought, I should have got a Corolla! $10,000 less, and gets 35 mpg? )

It's time for coffee & donuts. I hope you guys solve the OP's problem.

 

sunday morning

 

i'll show you mine, if you'll show me yours.

 

Unless her 'fillups' are just in the 3 to 4 gallon range, I'd say that isn't enough to be the problem. While it could be a contributor, something else is still happening too. And the displayed 80 mpg isn't consistent with E85 FlexFuel.

 

Nothing wrong with her Prius.
Operator error.

Just drive it....

 

Just like the old PEBKAC computer error - "Problem Exists Between Keyboard And Chair"

PEBSWAP - Problem Exists Between Steering Wheel And Pedal

 

loose nut...

 

Ahhh... You are still missing the most critical information we all on this thread want to hear. How many gallons of fuel have you put into the car for three so called "fill-up" during the 427 miles you drove. That is the only information you need to provide to us to determine, if your mpg is really that bad as you say it is.

For resetting Trip meter you just press long hold (TRIP) button on the steering wheel while this Trip A miles is displayed.

 

OK, in CA, the gas is like $3.50/gal, isn't it? The total fuel cost is $72.49. So, that's about 20 gal of gas used for 427 miles driven. That makes approximately 21 mpg, which is way too low for a brand new Gen4 Prius. Since we don't know how much gas was in the tank when you first drove off the dealer's lot, this number maybe bit off, but gives us good idea that your mileage is much lower than what the car is displaying. If you are planning to do some driving from now till you are taking your car to the dealer, you can fill the tank now, and record odometer, and drive until right before you visit the dealer and fill up again and record odometer. (You can also use Trip meter but there is a remote possibility that the meter is off. Odometer should be accurate, though it could be off as well.) Calculate distance driven since the last fill-up, then divide that number by amount of gas in gallon the car took for the second fill-up. If your mpg is lower than 40 by this method, your car has problem. Keep all those records, and present them to the dealer.

 

And ALWAYS keep your fuel receipts. You rarely need them, but if you do need them, you really need them. If you get a tank of bad gas someday, you'll be really glad you had the receipt. Or, if you are having issues like now, you'll also be glad you kept receipts.

 

Regular 87 fuel only! Have you been using E85? I have no experience with E85, but there are some discussion on the subject on this thread. I don't know the actual effect of using E85 on Prius, but it is not to be used on Prius, that is for sure.

 

I filled my 2016 up one month ago today and the next time I drive it it will be going over 600 miles on this tank and I always run the A/C as much as I want. My driving is all local and none over 55 mph but just an example of what the Prius is capable if driven very easily.

 

E15 is ethanol content 15%. 87 is for octane rating usually used for Regular gasoline. In our region we only have E10. For E10 in our region, and presumably for E15 as well, there are different octane rating higher number is for premium gas and cost more, but it is well discussed here higher octane premium gas do not offer any benefit to Prius. Prius needs Regular gasoline with ethanol contents upto 15%.

 

87 - 89 - 91 - 93 is Octane rating. All are safe, though 87 is what you should use.

E85 - E15 - E10 - E0 is Ethanol content. E85 is a NO-NO, just as the red slash says on the gas cap.

Here is a pump image from someone else recently, from post #47 of this thread. While 87 is best for your car, any of the four on the right, in gray or blue, are acceptable. The one on the left, in yellow, 85 or otherwise, is NOT acceptable:


The blue one, labeled Octane 88, is also E15. The gray ones are usually E10, though sometimes can be E0.

 

So, have you been putting E85 into your Prius? Though I have no technical information to offer you, that might explain the way off mileage you are getting on your brand new car.