Volkswagen ID.7 electric sedan to have a range of ‘approximately’ 700 kilometers – Picture and sound – News

Since that range is useless if you really want to use it, you need that 700km if you drive a lot on the highway, but I’ll be surprised if this ID7 gets 500 on the highway. Yes at 50 per hour you can get to 700, maybe even further, but at 50 per hour you don’t need a range of 700km.

A car always consumes more the faster you go, it seems logical, but that’s not what we’re used to. After all, that ICE consumes less fuel on the highway than if you drive it at 50, the reason being that an ICE very inefficiently converts its fuel into motion at a, to easily calculate, 75% loss (mostly lost to the heat that discharged through the radiator).
So what happens with an ICE on the highway is not that the energy demand is lower, because of the continuous demand for power, the loss is more limited, so that you can still drive fast and consume less.

If we take a diesel car, diesel contains +/- 10 kWh of energy/litre. If it consumes 6 litres/100 km, it has in principle used 60 kWh of energy, but 75% of it is lost, meaning it needed 15 kWh/100 km to drive efficiently.

An electric vehicle is 90% efficient, so to meet the same required demand of 15 kWh/100 km, it needs 16.5 kWh/100 km of energy. Since an EV doesn’t have a huge heat loss because it’s converting virtually all of its fuel into (waste) heat, count on 20kWh/100km in the winter.

With a 77kWh battery pack and the same energy demand as a diesel that consumes 6l/100km today, I get 466km in summer and 385km in winter, inaccurately calculated in theory but very close to what they do today electric vehicles.

There are no miracle solutions to make an EV even more energy efficient, you can take some weight off it, a little less air resistance, a heat pump to cut that heating down a bit, but in conclusion, the spectacular improvements have been around for a long time when electric vehicles were not yet the case.

So I look much less at what the manufacturer claims about range, but much more at how big the battery pack is, which I divide by 20kWh/100km, which is still very favorable given that there aren’t many EVs that actually they make 20 kWh /100km at 130/hour (mine also drops to 25 kWh/100km).