It’s slightly complicated by where you live (regional cost differences), how much “normal” electricity you use and at what times and how much and when you want to be able to charge the car.
I’m currently (no pun intended) debating swapping onto Octopus Agile, while I’d probably save maybe 25-30% on my normal usage I’ve already moved heavy use (washing machine, tumble dryer, dishwasher to the off paek rate of 7.5p on Octopur Intelligent Go.
I think that as my usage increases in the Winter I may swap over.
A handy place to check rates for Agile is here, shows real time rates for today and tomorrow,
https://www.octopriceuk.app/agile
Please excuse spelling/typos. Apart from being a clot it turns out I had one on my cerebellum that's now causing various problems!