The appropriate percentage on cars with zero emissions and electric only mileage of over 130 miles (such as the Nissan Leaf or all Tesla Models) are 16% in the current tax year, from 2020/21 this reduces to 0%, increasing to just 1% in 2021/22.
Using a Nissan Leaf as an example, the P11D values for these 3 tax years with fuel and a van with fuel are per the beneath table. Please note the van benefit value has not been confirmed for each of these years but has historically only changed a small amount year on year. The figures below are therefore estimated using the existing van benefit values.
Per the above table the most tax efficient option, by some way, for future years is the Nissan Leaf or another vehicle capable of a range in excess of 130 miles.