A really light car would either have to be limited to a very low speed or be terribly unsafe in case of a crash. Since lightness implies small size, it would also not have other desirable properties of cars, like their ability to carry passengers and cargo.

That said, there might be something to it:

1. The "bicycle that's more like a car" angle: https://www.youtube.com/shorts/H0jtCfdvwH4, https://youtu.be/9B0eXmbrBIo?t=30

2. The "car that's more like a bicycle" angle: https://www.youtube.com/watch?v=B9ly7JjqEb0

Seeing as we’re talking Paris, there are plenty of Twizys around. Not light light, but a third the weight of even a new Renault 5 EV. https://en.m.wikipedia.org/wiki/Renault_Twizy

Mm.

Now that I see it in real life I don't know how I feel about it. It doesn't feel safe when I see a Twizy, but when I see these cars in my mind I see them on Swedish bicycle roads.

The whole thing would probably require a total transformation of city travel.

The regulatory regime will take a minute to figure out, but with tiny vehicles like this + good transit + closing streets to regular big cars, we'll figure it out.

The basic ones (and things like the Citroën Ami) are more A-traktor than bicycle – there’s an A-traktor registered Ami in the next village along from me – but that’s typically a software limit. The Twizy could be bought in an 80km/h variant, and there are “remaps” that will take that version up to 110km/h.[1] I’ve seen them doing near that on riksvägar here.

[1] https://en.twizyx.com/

Cotroen ami

https://www.citroen.co.uk/ami

Aptera is shooting for 2,200 lbs with enough performance to handle highway speeds with two people and some cargo. It has three wheels and extreme aerodynamics.

https://aptera.us/article/how-does-the-weight-of-aptera-comp...

Looks like the Renault Twizy is only 990lbs with a 28 mph top speed, so a much smaller vehicle.

This is certainly a possibility for city cars. In the Netherlands there are a lot more 45kph mini cars driving around now. They were a thing in the past with moped engines but with electric drive trains all these solutions become much more viable. With the low speeds crashes are also less dangerous so everything becomes lighter.

A similar thing is happening with electric bikes and scooters. This was all possible with gasoline but with the lower mechanical complexity this is really taking off.

This results in a wider range for bike like vehicles which replaces a lot of car trips.

The real hurdle to people getting rid of their mostly stationary cars (not everyday for work drivers) is that renting a car is a horrible experience and car shares are also bad mostly. But as the space for personal cars shrinks I suspect this will improve over time.

You just don’t want to crash with something like that. If all cars were build like that it might even be ok but try crashing into a normal sized car…

> What if the cars were made really light?

That is the best answer.

For a little while in the 80s (remnants of the fuel crisis of the 70s) this was the trend. Go light and then efficiency is guaranteed. Combine with a small efficient engine and that's the optimal solution. A CRX HF from 1988 could do 44 MPG, with an engine that compared to current fuel injection technology is very crude and inefficient.

I want to buy a car that is basically this CRX HF but with 25+ years of engine and materials improvements. It could easily be a 1500lb car getting 60MPG.

But, no. Manufacturers (to some extent forced by terrible government rules) have gone heavier and heavier and heavier and heavier. Which is worse in every possible way.

Colin Chapman had it right: simplify, then add lightness.

And then as cars get heavier and heavier you also have people scared to drive smaller/lighter ones for fear of safety.