posted 2 years ago

MPG Marathon Cars Exceed Official Fuel Consumption Figures

New Cars Eclipse Manufacturer’s Fuel Consumption Figures

The MPG Marathon has crushed the myth that cars cannot hit their manufacturer's fuel consumption figures. As such, a Peugeot 208 GTi thrashed its target by 23.99% by averaging 59.39mpg rather than 47.9mpg. And this was not over a route designed to flatter. It excelled, in fact, over a two day event that covered more than three-hundred miles and competitors could not save fuel by driving slowly as they would have been penalised. Furthermore, the 208 GTI was not the only high achiever. The Peugeot 308 HDi 92 thrashed its target by 10.41% by returning 82.04mpg rather than 74.3mpg - and the Honda Civic 1.6 i-DTEC EX also exceeded expectations by 8.12% (84.87mpg/78.5mpg). In fact, the majority of cars broke their targets by a meaningful sum. But how? The key was to drive smoothly and maintain consistent velocities rather than speeding-up and slowing down. Within this, competitors kept engine revolutions low and lifted-off the gas rather than braked (where practical). The drivers also maximised aerodynamic efficiency by keeping the windows and sunroof shut. Finally, they ensured that the tyre pressures were correct, switched-off the air-con and minimised weight by abandoning unnecessary cargo.

How Fuel Consumption Is Calculated

A car's fuel consumption figures – assuming it has a traditional internal combustion engine - are calculated via the urban/extra-urban tests. These are performed once it has covered at least 1,800 miles so the engine is properly run-in, i.e. at its most efficient. The urban test is performed on a rolling road in a laboratory that has an ambient temperature of 20°C to 30°C. Furthermore, the vehicle must have been stationary for several hours so that the engine is cold. The test requires the subject to perform a series of accelerations and decelerations. It must also maintain consistent speeds and idle while stationary without moving forwards. Within these manoeuvres the vehicle's maximum speed is 31 mph, it averages 12 mph, and covers 2.5 miles. In contrast, the extra-urban test represents faster routes such as a-roads and motorways. This is performed immediately after the urban test and once again includes a series of accelerations and decelerations, etc. However, the vehicle's maximum speed rises to 75mph and it averages 39 mph over 4.3 miles. The combined figure is then calculated based on cumulative results. Clearly, such figures can be achieved away from a laboratory but it takes effort, skill and patients.