The little petrol cars are on a par, or even slightly cheaper I think...
I am still not convinced they are to be honest, apart from the other gains over ICE cars like smoothness to drive and as you say, no emissions and no road tax ( yet ).
However, my wife has very small ( so called ) economic Fiat 500 1.0 litre.
She loves to bits - We have owned it from new and it is serviced regularly.
It has only covered 14,000 miles and was registered back in 2016 !.
You would expect the Fiat to be cheaper to run than our ZS EV facelift, given its small size, as you can’t get much smaller car really.
I actually find our ZS EV more economical to run !.
That may sound strange, but it true.
Comparing the two cars is like night and day.
The Fiat is cramped and very under powered, to the extent that overtaking can be that nerve racking, you just don’t bother.
Insurance is not far behind the ZS and you have to tax it as well !.
Servicing costs are about the same as the ZS also.
The fact that the Fiat has covered so little miles, goes some way to make this story believable.
Or previous ZS EV ( Gen1 ) covered 20,000 miles in two years and the new facelift model has covered almost 7,000 miles since mid March 2022.
We are both retired and travel almost everywhere together.
It’s hard to find a case to say that the small ICE car is cheaper to run in our case.
Important to say that we do have the facility to charge from home, which is vitally important to keep the EV running costs justified.
I personally think I would still have an EV over a ICE even if the cost was very close.
EV’s are a habit that is hard to brake for me.