31.7.2014Real World MPG league table published
Emissions Analytics have examined their fuel economy data in more detail, to particularly look at how different manufacturers perform.
Of the 459 vehicles included in the study, spread across 26 manufacturers, the average real-world miles per gallon by OEM (Original Equipment Manufacturer) ranges from 31 to 54mpg, with a mean of 44mpg. The deficit from the official figures ranges from 7% to 23%, with the average 22% below NEDC.
The graph below, ranks manufacturers (excluding manufacturers where fewer than five of vehicles were tested) according to the extent of their variance from official figures. It reveals some interesting observations.
Three of the OEMs towards the right of the graph with lower mpg are performance-car-only manufacturers, specifically OEMs 19, 23 and 26. If excluded, then the range of real-world mpg shrinks to 40 to 54mpg. By comparison the NEDC figures for these vehicles range from 50 to 63mpg, almost the same spread but 20% higher.
There is then one outlier that does worse than average (OEM 10) and two that are significantly better (OEMs 21 and 25). These manufacturers may have a model range which causes this skewing effect, for instance if they have few big cars in their model mix their average mpg could appear better than other manufacturers. When these three OEMs are also removed from the analysis, the miles per gallon narrows even more from 42 to 49mpg.
Despite the remaining 20 manufacturers representing a variety of nationalities, technology types and target audiences, their vehicles have surprisingly similar performances in the real world. However, the variance from the official figures still ranges from -13% to -24%.
Although Emissions Analytics promised to keep the information anonymous, they did however let us know the top performer which has the smallest variance from the official combined mpg, was Porsche (OEM 26). It also has the second lowest absolute performance, perhaps not surprising given its model line up.