Most people will agree that cars have seen a huge amount of development over the past 40 years. They are more reliable, more comfortable, better equipped, less prone to rust and easier to drive than the cars that filled the streets in the 1970s.

They are also much bigger and heavier. Just take a look at some side-by-side photos of classic models that have been around for years such as the Mini, the VW Golf or the Ford Fiesta. The modern-day versions look as if they spend their days curled up on the sofa munching pizza and watching back-to-back episodes of Jeremy Kyle, compared to their lithe ancestors. 

Three little words

Given these other advances, it seems strange that in this singular aspect, cars have gone backwards over the years. After all, weight is the panacea that cures all ills in the automotive world. The less weight your car is carrying, the better its fuel economy, acceleration, handling, braking and environmental impact.

The three little words that inspired automotive innovators, such as Colin Chapman and Bruce McLaren, to produce better, faster racing cars in the 1960s are: Make it lighter.

Why so flabby?

So, what has caused this bulking out to such an extent that a modern Porsche 911 weighs 35% more than the classic version and its own inspiration, the VW Beetle, has increased by 63%? There are two main reasons.

First, drivers and passengers demanded more creature comforts. Thicker, plush seats, additional layers of soundproofing and a raft of electronic gadgetry all added to the overall weight.

The second reason was the dreaded crash tests. Manufacturers needed to score well in the safety ratings, meaning the cars had to pass the crash tests, meaning they started to build them like tanks.

This increase led to a third consequence. All this extra weight meant the cars became slower and less agile. Colin Chapman would have found a way to pare off some weight, but for the major manufacturers, the solution was simply to put in larger engines, tougher suspension and bigger wheels. All these additions made the cars heavier still. 

The times, they are a-changin’

So much for the bad news. The good news is that while the early 21st century might go down in history as the period when cars got flabby, manufacturers now are working on getting them back in shape, with a certain degree of success.

Top of the class is the latest Land Rover Discovery, which is 465kg lighter than the outgoing model. Of course, when you add that the latest Disco still tips the scales at more than two tonnes, you could argue that it was not just overweight, it was clinically obese, and it is still almost double the weight of its ancestors.

However, it is a step in the right direction. People are never likely to eschew their creature comforts, but the key to weight reduction lies in the use of aluminium and even carbon fibre instead of steel. However, none of these materials is inexpensive. As Chapman and McLaren found all those years ago, there is no easy answer.