Which leads us back to one other issue that we seem to have overlooked.
Cars are getting heavier all the time. Thanks to extra emissions control equipment, rigourous safety standards and the escalating list of optional extras, cars are much heavier today than they were 20 years ago - in some cases by as much as 75%.
A Golf GTI today might have double the power of it's original ancestor, but it's nearly double the weight. That the extra energy needed to propel the extra mass is not unduly at the expense of fuel economy speaks volumes about modern engine design.
In addition to new hybrid technologies and exotic fuels, we also need to pay attention to how we manufacture our cars. Bucking the trend, a Jaguar XJ saloon is actually lighter than it's predecessor by virtue of switching to aluminium instead of steel for the bodyshell.
There are inherent problems with aluminium; it's much harder to work with than steel, is softer, requires more energy to produce and is as a result costlier, but is a step in the right direction. Mass produced. composite bodied cars are also some way off, although some companies do use plastic (non load bearing) panels to reduce weight.
