I was stunned to discover the weight figures for the Renault Eolab plug-in hybrid concept that debuts at this week’s Paris auto show. A deeper investigation revealed some interesting calculations.
Renault’s release on the car says the 955kg Eolab is more than 20 percent lighter the Clio. Another figure touted was that it is 400kg lighter than the Clio.
Based on that information I did the math using the lightest new fourth-generation Clio, which weighs 980kg, as the starting point. The results were 784kg and a startling 580kg. Could those numbers be true? No.
Renault made its claims using these calculations.
- The new Clio with no extras weights 980kg. The benchmark model used for the Eolab’s comparison figures is a Clio Energy TCe 120 EDC, which weights 1,210kg. Renault deducted 400kg saved from the Eolab’s lightweight construction but added 145kg for its plug-in hybrid powertrain, which it not available on any current Clio, thus obtaining 955kgs (1,210 – 400 + 145 = 955kg).
- Also, the 955kg weight figure is more than 20 percent (almost 21 percent, to be precise) below the 1,210kg of the model use for the comparison.
Renault’s math is complicated – and questionable – because as you change the reference model you can increase – or decrease – the weight saving figures and percentages.
This funny math, however, does change the car’s fuel consumption figures: 1 liter of gasoline per 100km (282 UK mpg; 235 U.S. mpg), equivalent to CO2 emissions of just 22 grams per kilometer. That is an astounding figure for a four-seat subcompact. The Eolab's fuel economy is nearly as good as Volkswagen XL1 plug-in hybrid’s 0.9 liters of diesel per 100km, but the VW model only has room for two passengers.