new car with very bad mpg

Are you saying this is a gen 4 Prius? All I have seen have either 15" or 17" wheels, not 16" Heavier rims, non-LRR tires, and low tire pressures can reduce fuel economy.
When I picked up my 2017 with 15" wheels a year ago, it said I got 59 mpg on the 150 mile drive home from the dealer. (US gallons)

 

i wouldn't worry, but i think most folks feel the gen 4 is a bit quieter.
check the oil level, and go back to the dealer and drive another one to compare.
i don't like comparing trip mpg, but would prefer tank fulls, preferably several. there are a lot of factors that can effect a trip, for better or worse.
do both cars have 16" wheels? the new tires might cost a couple mpg's until they are broken in.
is it colder there? winter formula petrol?

 

Nice choice of color. I like the black roof too.
Was there any difference in the trim levels between the Gen 3 & Gen 4? Some people notice road noise more in the lower trim Gen 4, depending on the tires. Toyota uses several different OEM tires on the Gen 4, likely depending on available stock.
Winter tires are generally noisier too. It could be just a combination of factors. Test driving another one is a good idea.

 

Do you tend to leave the Nokian tires on all year? If not, a drive with the OEM wheels could help narrow down the possibilities.

 

can you record the sound and post it here?

 

some people say a new car needs break in, but i have never experienced it. maybe get both cars to the dealer and have a mechanic listen to both engines.

 

When reading that, this is popping into my head :



What size are the tires? Maybe they're non-stock, different outside diameter? If they're significantly larger outside diameter that could throw off the odometer and increase wind resistance. What are the tires too?

Also, what speeds were you travelling? MPG drops very significantly and fast at sustained high speeds, for example.

Addendum: maybe there's a stock 16" tire in your country, I'm likely completely off the mark on that, sorry. But yeah, what speeds were you doing on this initial drive? High speeds will depress mpg.

 

My experiences are the opposite. Engine sound and ride comfort are improved over previous generation (I did have 17 inch wheels). MPG is reduced in winter time for sure as you know. If issue persists after a couple tank fill and tire change then have the dealer run a diagnostics and check the engine compartment for any loose panels or covers. Your car looks sharp, good luck.

 

215/35 r17 - would give you a different rolling circumference from the original (215/45R17). That would make a substantial difference to both your speed distance readout as well as your mileage calculation. The 16" wheels are only about 1% different from the originals though.

I would never take much notice of the 1st trip, nor the first fill. And the dashboard display is only a computed figure from a number of sensors, and can be a few percent out (though generally optimistic).

You need to completely ignore the first one, fill the tank (first click only) even if the dealer says they've filled it, zero TRIP A, drive for at least ½ a tankful, fill and calculate with a spreadsheet or calculator.

 

We do not know if the fuel from the canister was fresh fuel. That could make the engine run rough. You

 

best answer.

 

I am very much delighted with my Prius Prime Petrol management. Very much a great investment


iPhone ?

 

How cold is it in Slovakia right now?

We are in the middle of a bitter cold snap where I live and as a result my MPG is at an all-time low.

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