Thank you Colin for these helpful observations.
Mostly I avoid very short runs. In UK most are about 15 miles or so to do shopping. Occasional longer runs. Speeds are usually about 30-50 mph.
In France runs are about the same for shopping and speeds a bit faster as the roads are clear. About 4 round trips of about 350 miles mostly motorway when speed is more or less constant 85mph.
I haven't ever bothered much with fuel consumption. I think in terms of full or empty! Petrol is a relatively small part of the cost of running a car. If you buy and change new ones it's trivial. I tend to buy a good example at about 5 years old and keep it until it starts to cost more to service than it's worth, or even longer if I like it. The inevitable odd scratches neither matter not bother me. The first one on your shiny new car must be very upsetting.
I dislike new cars. They smell horrid, everything is stiff and differs from its predecessor. My experience has been that they often go wrong soon after you buy them and depreciation is massive.
Although I still enjoy driving I regard a car as a useful tool and instrument of freedom of choice. I like it to be comfortable, quiet, big enough to provide for my needs and easy to drive. A few bells and whistles are nice if they enhance safety or the driving experience.