My calculation is very simple My Mercedes C300 uses premium gas. I average it at 7 km per dollar. That is it will cost me $14 for 100 km.

It takes 2 hours to charge 100 KM in model 3, and at 8 KW per hour, it will take at most $1.60 to get 100 KM (at $0.08 a kw, with everything else, it will be around 10 cents per kw). For argument sake, let's just said $2.00, that is just 20 percent of what I used to pay in gas.

The 20% is quite close to what everyone is saying here. In winter, it may goes up to 30% to 40%, Whatever!

Not to mentioned it is just plain fun to drive even after 9 months. It is less stressful to drive, and from time to time, I got some interesting new features with this TOY. Who else can do this for us at regular interval and at no cost to us. Best decision ever.