On my current car the total costs over the 4 years on lease was £10k less than on PCP. I didn't/don't believe the car's value in 4 years would be anywhere close to £10k higher than the residual value. Had it been £2-£3k difference then I may well have gone for it and been happy to potentially to "lose" that amount for the flexibility PCP gives.
My calculations show loan is best....
From my 2019 SR+ purchase:
37k car (after grant)
35k loan (from the bank - zero deposit) plus 2k tradein.
18 month later had 25k remaining (including £700 early repayment charge)
Sold the car for 32k and had 7k left over.
My total spend over 18 month was 5k (not including electricity and insurance etc.) zero service obv. so 278/mo. If you include the EAP I bought which was not valued at all it comes up to 8.5k. 472/month.
I drove 14k miles
Now I got a LR. Car is 51k -3k grant = 48k, Interest is 5.1k So total of 53.1k. minus 7k deposit (from car sale) my payments are now ~£630 over 72 months. Credit of 41k.
IfI sell this car after 18 months like the last one (no plans to do so, but *sugar* happens) I will have repayed ~630*18 of the loan, leaving ~ 35k left on the car. If we take the same loss of value as I had on the SR+ (40k car selling for 32 ~ 13%) and apply it to the LR (51k car, 13% of that is 6.6) an LR will sell for ~ 44k in 18 months.
so if I have 35k left to repay, and I sell the car for 44, I'll have 9k left over.
Of course these cars could depreciate much more, but point is you will get your deposit back. With PCP or lease, you wont. With PCP my bet is that you would be better off buying the car and then selling it. It actually doesent lower the monthly amount that much, so not sure what the point is. Lease is just daylight robbery....