[Vekke]

I will soon get my own first eletric car and it will be the VW ID3
Frontal area is 2,36m2 and announced drag coefficient Cd 0,267.

Cars oem tire size is 215/55R18 which is not super wide, but still not super narrow either.

Car is already pretty energy efficient, but ofcourse there is room for improvements as the drag is 0,267 which in my mind is pretty high.

Testing and changing will begin from tires. I already have bougth BMW I8 20" aerowheels and 195/55R20 Nokian Hakkapeliitta R2 winter tires which have A rolling resistance mark. Those wheels are almost fully closed.

I also have the 155/70R19 wheels and tires from A8 project, but for those I have only summer tires at the moment. But surely I will test also those when weather gets better. Will try also with wider wheels at rear like they are in the I3. Specs on these vehicles are pretty close as
BMW I3 CdA 0,714 vs VW ID3 0,63 The bmw is 400kg lighter so it consumes little less energy at lower speeds about 10% . But when speeds go to 140km/h difference is only under 4%.

Roofline of the ID3 matches perfectly the ASTII template so the bad aerodynamics come from wheels and underside of the car as the front already has a active grill block on all models. Will look closer is it full grill block or not when I get the car.

Disclaimer:

Don`t believe any of the results and ideas presented in this topic, you might save some energy. All the testing is highly questionable on the measurement reliability perpective. If you believe you can only measure road changes in the accuracy of 2% then just take that much lower figure down on the total savings percentage you have your value how much better energy consumption you migth get. Everything depends on your car setup and the outside conditions you are driving. I have tried to put the details here what you should take into account when doing mods like grill block. I don`t take any responsibility what you do to your vehicle.