Average Fuel Consumption Accuracy

[Andy Thomas]

How accurate do people find the Average Fuel Consumption indicator on their Auris.

I have now owned my Auris for a month and I find the actual consumption when filling the tank to the top each time is approx 2 mpg less than the indicator.

Andy.

[Mooly]

I'd say that was well within an acceptable tolerance particularly when you realise how the reading is arrived at and calculated. The actual flow of fuel isn't measured, it's derived from knowing how long each injector is open and the amount of fuel that would pass in that time interval. Those values are then combined with speed to arrive at an average mpg.

My Corolla TSport used to over estimate by around 2 to 3 mpg. My Auris 1.33 is tbh amazingly accurate over brim to brim fills, to within 0.5mpg which is remarkable.

As to you having a problem... no, it's fine.

[tavy]

I find my average fuel consumption indicator very accurate; the trip computer calculates instantaneous consumption relying on fuel mass that is calculated dividing air mass (red by MAF sensor) to AFR (air-fuel ratio) , then it's very simple for computer to calculate average consumption ... For those engines that haven't MAF sensor, average fuel consumption indicator isn't so accurate because they calculate consumption dividing consumed amount of fuel (estimation that is made relying on fuel gauge - pretty inacurate) to covered distance.