How so, the mk2 focus 1.6 improved, as did the mk3 and 4. Not to mention the fact that over that time the 1 litre is more powerfull and has a higher mpg. I know not all improve but i bet on average for the same power output mpg increase.
There were really big MPG improvements between the mid 70's and the mid 80's (You know, after the Oil Shock)
By the mid 80's early 90's medium family saloons with MPGz in the 40's were not uncommon.
Some were truly exceptional (anybody remember the 2.0 Montego TD? High 50's/Low 60's was not uncommon. There was even reports from some "Hypermilers" getting nearly 100!)
And then it sort of stalled.
I remember reading on a US site a couple of years ago where somebody was having a good old moan along the lines of "Where the
**** is my 45MPG Civic?? I had one in 1979, why cant I have one now??
(And remember, US Gallons are a good bit smaller than ours whilst the Miles are the same!
)
And he had a point too.
Of course, Modern engines probably are a lot more efficient than the engines of 30 years ago. But, the cars are also a lot heavier (Particularly the smaller ones) and they also produce a lot less pollution.
So they are safer and less polluting, improving both of these saps power so the engines have to be more powerful to get the same performance.
Even if the engines are more efficient, the fact that they now need to be as much as twice as powerful to deliver the same performance as an equivalent car from the 70s means that they are still going to use more fuel.
Concord was, apparently, one of the most efficient machines ever built! Yes really! I remember some years ago reading that the Concord engines at cruise had a thermal efficiency of over 55%! that is into fuel cell territory!
I can not confirm is this is actually correct, it is just something that I remember from somewhere, but it wouldn't surprise me Concord had some very interesting features that ensured high engine efficiency at cruising speed (EG the supersonic shock wave was designed to supercharge the engines at cruise speed). In any case my point is that just because something is "Efficient" doesn't mean that it is "frugal"! Flying at twice the speed of sound still takes enough power to run a City. (4 Olympus Engines at full chat is around 250Mw IIRC) Even if it is 100% efficient you are still going to consume a
****load of fuel transporting a bus load of people across the Atlantic!
(Again, I am sure I remember reading somewhere that Concords take off weight was over 50% fuel. More like a rocket than an aircraft really!)
In the same vein, Modern engines may be more efficient, but the greater demands that we put on them in terms of our expectations means that the economy advantages from this have simply never been realized (Well, not in terms of obvious MPG improvements anyway Of course I acknowledge that reducing pollution and improving safety are also benefits in their own right)
There were plenty of cars from my youth, long before expensive and difficult to repair electronics become compulsory, that
easily achieved MPGs well into the 40's and beyond.
If one chose to shoehorn an appropriate modern engine (Say, around 60BHP) into (Say) a 1970's Vauxhall Chevette, and strip it down so that it had none of the emission control technology (IE with MPGs as the only priority) I have no doubt that you would probably get around 100MPG out of it, possibly even more.
