fuel flow indicates zero - engine keeps running

Switch to what? The average and other on HSi are l/100km

 

Switch to how many km you make with one Liter of fuel, which is equivalent to the MPG. L/100km is equivalent but less geared to how much you get.
L/100km - how much you need.
MPG-km/L how much you get.

 

I agree there is something weird here. Normally, if the car is not moving, speed is zero, so L/100km is mathematically undefined because there is a division by zero. The mathematical limit of the fuel consumption when speed gets close to zero is infinite, but the actual consumption in L/100km is undefined if the vehicle is not moving.

What the Prius software does in such a situation is to display an instant fuel consumption of 0 L/100km. I think it is misleading. The reason is: when the car is idling (engine running, car not moving), we can see the average fuel consumption progressively increasing. So that is kind of weird to see instant fuel consumption to be 0 and average consumption increasing at the same time. Both displays should agree.

If the computer is set to display miles instead of km, then fuel consumption is displayed in MPG. Now let say the car is running in stealth mode - no fuel is being used, but the car is moving. In theory, the number of MPG is also undefined, because no fuel is being used (again, a division by zero). Yet, when the car is in stealth mode, as far as I can remember the MPG instant display goes to max (can anyone confirm that?). That agrees with the average MPG display, which progressively increases with time when the car is in stealth. So in this case, both instant fuel consumption and average do agree, in spite of the undefined operation.

To me, that qualifies as a software bug. When using km, for both displays to agree, instant L/100km should display max when engine is running and car is not moving.

 

it's not wrong... if you leave the engine on long enough your effective MPG will go down it is still factoring in the 0mi/gal even tho the car is still stop'd it stops counting when the engine is off. when the engine is on make no doubt it will hurt your average.

 

kash,

Please read my post again.

Also note that L/100 km work the opposite as MPG. The lower the L/100km, the lower the fuel consumption.

CivicQc

 

I believe it is within Toyota's design specification.
0 L/100km is displayed when ICE is running at standstill.
max mpg is displayed when ICE is stopped at stealth driving.

Ken@Japan

 

Is there any way to change over from l/100 to km/l
I really prefer it that way

 

The international standard for measuring fuel consumption is litres per 100 kilometres (SI units). Kilometres per litre is measuring mileage but as we are not dealing with miles but kilometres measuring mileage is silly.

Litres per 100 kilometres is fine once you are used to it, don't convert, live with the system. Low numbers are high scores.

 

You can always look at the display upside down.

Tom

 

True but old habits of over 30 years (driving) are hard to break

 

As explained by others, fuel consumption shows as 0 when the car is stopped. As soon as a speed shows up on the display, fuel consumption will show again.

Toyota chose to show 0 L/100km in such a situation instead of "infinite" L/100km (X Liters divided by 0 km).