Fuel range figures

[ikcdab]

So today my Yaris cross says:

Fuel in tank: 96%

Range : 377 miles

Average mpg: 60.7

I can't compute these figures. Tank capacity is 36l.  At 96% thats 34.5l or 7.6 gallons.

Range estimate of 377 miles therefore means 49.6mpg.

So how is the range figure computed by the car? Yesterday I got 80mpg on a journey and our average figure is gradually creaping up. The range figure makes no sense.

[Roy124]

Ian, range is to the Reserve and not to empty.

Rework you figures using 377/96*100/60.8 and convert to litres.  It will around 29litrs

[jthspace]

They are "assumptions", you got 80mpg on one journey but your average is lower but slowly going up.  Assuming it's 50 MPG and you got 80 recently, then an average assumption on recent journeys is 65 on these figures, about what the car is assuming in its calculations.  The only accurate (!) measure is the fuel gauge.  My fuel gauge is very slow to drop to half but rapidly goes to low, it's definitely not real-life fuel usage 🙄

[Roy124]

22 minutes ago, jthspace said:

They are "assumptions", you got 80mpg on one journey but your average is lower but slowly going up.  Assuming it's 50 MPG and you got 80 recently, then an average assumption on recent journeys is 65 on these figures, about what the car is assuming in its calculations 🙄

And the mileage at 50 equals the mileage at 80.

Now I am at home, I reworked the figures.  It comes out at 29.5litres which equates to a reserve of 36litres.

While gauging consumption on tank to tank might appear more accurate remember fuel pumps are calibrated at 15°C  and your usage will also vary with temperature. 

[ikcdab]

20 minutes ago, Roy124 said:

And the mileage at 50 equals the mileage at 80.

Now I am at home, I reworked the figures.  It comes out at 29.5litres which equates to a reserve of 36litres.

While gauging consumption on tank to tank might appear more accurate remember fuel pumps are calibrated at 15°C  and your usage will also vary with temperature. 

Thank you that now makes sense.

36l minus 6l reserve at 96% gives 28.8l available which is 6.3 gallons.  It's saying 60.7mpg which therefore gives 385 miles.  So that's correct within the rounding.

[Serban]

Well it's cold ish weather now. Full tank, reset mpg and when you reach almost empty fuel tank you'll have at least 60mpg and 450 miles driven I say unless idk you do loads of short trips and use AC a lot? It's not that cold yet though.