I recently went the same way John and handed back my scheme car and bought privately, handed the scheme car back at the dealer I was getting the new one from. Only a 140 mile trip there and back.
I Can only drive an automatic now and use adaptive cruise alot as it really helps with my condition. I know I could get better mpg if on a journey if I drove it myself or clicked the speed down a bit when coming to a hill etc and you see the mpg drop but really cannot be bothered with all that.
I had diesels for many years but due to covid and other reasons I’m not doing anywhere near the mileage I was and kept getting DPF issues as alot of driving now is real short distance’s. So the last two cars have been petrols and the latest is a suzuki vitara 1.4 boosterjet mild hybrid.
Actually am liking it, i might try driving real slow just to see how well it could do, but i know it wouldn’t happen on a regular basis.