How are manufacturers approaching green car development?

While the move away from the loud and obnoxious engines of the past may be seen as a sign of boredom for some, in reality it's anything but. Sure, green cars on the whole are quieter and more environmentally friendly than their petrol-drinking counterparts, but the development processes these manufacturers are taking are arguably more exciting than anything seen before. 

The excitement is due to the fact there isn't one clear solution that is undisputedly the best way to create cleaner motoring. Some manufacturers have found success with all-electric engines while others are still experimenting with petrol-electric hybrids. 

These manufacturers are also taking their own unique processes to testing these technologies, including in-depth laboratory development, road-testing and even subjecting them to endurance motor racing. Here are three that have caught our eye. 

Tesla Model S - A clean slate

This is a vehicle that is set to change the automotive world as we know it, and the surprising part isn't even the ridiculous numbers it produces. It reaches 100 kilometres per hour in 2.8 seconds, faster than most supercars, yet it can seat an entire family. No, the most surprising aspect of the design is that a more established automotive manufacturer didn't create one first. 

Maybe that's the key though, while other manufacturers tried to make existing models more fuel efficient, Tesla simply built one from scratch. 

Audi and Porsche - Le Mans legends

The Le Mans 24-Hour race is one of the most testing events in the sporting world, challenging a machine to handle a full day's worth of constant driving - day or night, hail or shine - at full race pace. 

In recent years, the regulations for the top class have changed significantly. In the past, it was about who could create the fastest car. Now, efficiency is part of the equation. All cars entering the LMP1 class must be a hybrid of some sort - it's up to the manufacturers to decide what they think is best. 

For example, the Porsche 919, victor of this year's race, marries an internal combustion engine (ICE) with a lithium-ion battery energy storage system, a pretty standard combination for green cars. The Audi R18, on the other hand, combines its ICE with a flywheel energy storage system. 

Google's driverless car - A mileage master

The other option - as Google has done with its driverless cars - is to simply put it on the road and prove that it works through rigorous testing. After all, this is what it will have to put up with once it's finally released. 

Google's machines have been braving city streets for a while now, and should be more than fit for fleet managers once they're eventually made available to the public.