Consumption SUV/Family Van

Hello, in view of the current CO2 debate, SUVs are becoming increasingly discredited by the public. I wondered why not talk about Family Vans, for example, which are similarly clumsy. So I compared two vehicles – with surprising result I actually assumed that such a Family Van is not more economical than an SUV. But with comparable motorization and weight, the Sharan consumes less than the Q5. But why? Especially? It’s not wind-sharp either. It’s not easy either. What’s it about? Engine control? Would interest me. The choice was of course arbitrary, but I still think that the two vehicles make a good comparison.