Friday, September 7, 2007
Good Estimate of Fuel Consumption
My colleague was telling me about her car's heavy fuel consumption and elaborated that it was an average of 400 km on about $70 tank of petrol. So how accurate is the estimate of fuel consumption? Fuel consumption is defined in my opinion as the distance in kilometres travelled per one litre of petrol (since we are using the metrics system of measure). $70 worth of petrol at a price of $1.70 per litre is only about 42 litres. Thus, her estimate is 400/42 = 9.5 km/l.
There is a more accurate way to track your fuel consumption:
Step 1. Fill your tank completely.
Step 2. Reset your trip meter.
Step 3. Drive till your fuel guage is low.
Step 4. Read your trip meter when you arrive at the pump for the refuel.
Step 5. Fill your tank completely.
Step 6. Write your distance travelled on your fuel receipt and you can compute the fuel consumption on the previous tank of petrol by dividing the distance travelled (km) with the volume of petrol added (l).
Step 7. Go to step 2.
You should do this continuously or at least several times in a cycle to get a good estimate because pump attendants practise personal approach to fill your tank - some rely on the auto-stop, some continue to add till the nearest dollar value, some continue to add to the brim, etc. You got to watch out for your paintwork if the petrol overflows, so observe if the attendant splashes water at your fuel inlet. The variability of the auto-stop also introduces some difference to the actual fuel added.
So, what is your accurate fuel consumption? My 5-year-old 2.0 MPV is still doing a 9.1 km/l.
New - Tool page is added.