How do you account for that? I always had the impression that old engines were very fuel inefficient, predating the oil crisis etc. And of course car makers used to often use very ancient engines even in cars that looked "with it" and modern.
Could be a number of things. Weight has been mentioned up thread (my Mini is a couple of hundred kilos lighter than the current runabout) but my suspicion is that the more modern car has been tuned for passing the standard EU lab tests rather than to give the claimed economy in real world driving conditions.
My Mini has the A+ engine from the 80s (developed after the 70s oil crisis mentioned) and could actually achieve the claimed 60 mpg if driven carefully (and before I modified it). More recent cars I've driven don't seem able to do that no matter how gently I drive.
I read up a lot from the tuning gurus before doing my tweaks and something that sticks in my memory was David Vizard's section on economy in his book. In those experiments he tried different carburetters and fuel injection and found that the SU carbs gave the best results, which he put down to the size of the droplets they produce being just right to give the most efficient burn in the A series engine. I wonder if the same applies to other engines and how much research has been done into it?
