We have just returned from a 3 day mini holiday from our home in Solihull to Teignmouth Devon. It was the first long journey we have done in the Venga and I used it to determine the accuracy of the odometer in the car and the fuel economy on a long journey. I brimmed the fuel tank immediately before starting the trip and immediately upon our return.
To determine the accuracy of the odometer I compared it with the distance posts on the M5 motorway from Bromsgrove to the A30 exit near Exeter – and with the distance given on my Garmin sat-nav .
The odometer trip B measured the distance as 142.2 miles
The motorway posts measured 234.0 km = 145.4 miles
The Garmin sat-nav measured 145.3 miles
Hence the odometer is reading 2.2% under the actual distance.
The journey down measured 182 miles on the odometer of which all but 21 miles was on motorway class roads. The economy trip showed 41.9 mpg at the end of the journey and a time of 3 hours 16 minutes giving an average speed of 56 mph.
During our stay in Devon we did 61 miles tatting about the villages. The trip economy for this period (which was stop start through the Devon narrow lanes and towns) indicated 32.5 mpg and an average speed of 21 mph.
The journey back home measured 174 miles (a slightly different route than for the trip there) with the economy trip registering 43.4 mpg in a time of 3 hours 28 minutes giving an average speed of 50.1 mph.
The trip A economy trip for the whole period since the car was brimmed over a distance of 417 miles showed 40.6 mpg. and a calculated average speed of 44.1 mph.
Using the above data I have concluded that the Venga averaged an actual economy of 45.6 mpg (6.2 l/100 km) on this tank/journey – but the car economy trip for that period showed 40.8 mpg. Hence my trip computer is under-stating the actual economy of the vehicle by a considerable amount.
Here is a copy of the spreadsheet I use to make an ongoing record of every tank of fuel.
I must admit that I am more than agreeably surprised at the indicated economy of the Venga. I had expected to get about 34 mpg around town and 38 mpg on long journeys. It will be interesting to compare this result with future tanks of fuel before I can be certain the results are accurate.
