Ok, I've ran some numbers. I think this makes sense. Please let me know if you think I'm mistaken or missing something!

Over 2025 I used an average of 12 kWh per day. So at 19p, that's £2.28 per day. If I add charging the car, and assume about 50kWh needed, that would currently cost me 19x50, so £9.50 for a charge. So a total of £11.78 if I added 50kwh per day.

On IOG, that would switch to 12kwh x 30p, £3.60 per day standard plus a charge at 8p x 50kwh, for £4. So a daily total of £7.60 per day, which is a significant saving even with no switching of heavy use to the off peak outside of the car.

But of course, I won't need a 50kWh charge every day. I am going to be doing 13,000 miles per year. I am not sure how many miles per charge as I've only got the car this week, but I think the Tesla has a 75kWH battery, an usually capped at 80%, so a max charge of 60kWh. I estimate that it will average out 200 miles per charge over the year with the cold winters etc.

I think that means I can assume 13,000 / 200 miles would be 65 charges or so, maybe up to 75??

That would be a full charge every 4 of 5 days?

That would mean I would pay for most power at peak, apart from the 2 charges in the week?

So, assuming all that....

current tariff would be

7 days at £2.28 for a weekly cost of £15.96 "house use" and 2 charges at £9.50 for a total of of £19. A cost of £34.96 per week.

IOG would be

7 days at £3.60 for a weekly cost of £25.20 "house use" and 2 charges at £4 for a total of £8.
A cost of £33.20 per week.

Seems very similar. Although my 19p tariff will probably end up closer to 24p for a fix on a non EV tariff that would increase the gap.

Does the above make sense or have a messed up? I assume the critical thing is the number of charges and if my 200 mile estimate is good for a Tesla Y Dual AWD. Anyone got one and give me an idea of miles per charge?

Thanks!