I believe they are free to not carry gasoline. The fact they carry it, tells you a lot.

I guess there's two reasons - the first is when they started this process it was before we had full electric vehicles and it wasn't clear what the best technology would be, at the time hybrid vehicles were very popular.

The second is that F1 has been carbon neutral for at least two decades with the FIA planting trees to offset the extraordinary amount of pollution that flying the F1 circus around the world generates. Even though reducing fuel does nothing to make F1 greener when you take into account the carbon generated by transportation it is important that the actual show is as green as possible.

There are a number of reasons for the fuel limit.

One is simply that the engine manufacturers want efficiency to be a relevant factor, because it aids in their R&D and marketing efforts. With a fuel limit in place, F1 becomes a showcase for both performance and efficiency.

Another vital reason is to limit speed and cost. Back in the 1980s, F1 was in the midst of a turbocharger-driven arms race. Manufacturers were adding more and more boost, which had a severe impact on both costs and safety. The high levels of boost severely stressed the engines, so teams were replacing the entire engine after a single race. Many teams were using "qualifying special" engines that were built with a lifespan of just five laps. The extra power was creating dangerously high speeds and the effects of turbo lag made the power delivery of these engines very erratic and difficult to control.

Many other racing formulas use a restrictor plate - a metal flange with a hole of a specified diameter that restricts the air intake of the engine, creating a hard limit on maximum power.

The hybrid versions do not outpeform what a petrol version could be, if it wasn't strictly restricted to a specified maximum engine volume and pressure.

Once upon a time, F1 used to be a "anything goes" series where the best in the world competed to build the fastest racing cars in the world. This stopped when it became easily possible to build a car that was simply too fast for a human to drive.

Since then, the racing series has piled on rules and restrictions meant to limit what the cars can do. Since the gasoline engine is hard capped, and they allowed adding an electric engine on top of that, you now need to use one to compete.

You've just brushed upon one of the biggest debates in modern motorsport. If you are interested in reading further there's many great opinion pieces on both sides of the fence. Here's one interesting piece written recently by ex-F1 driver Stefan Johansson [1].

[1] http://www.racer.com/more/viewpoints/item/143400-johansson-m...

It's attractive to the manufacturers. F1 is stupendously expensive, so manufacturers want to get maximum bang for their buck in terms of marketing. Trickle-down technology is a major marketing hook, particularly for McLaren and Ferrari. Both companies introduced KERS- and DRS-inspired systems on their road cars when they were added to the F1 rules.

This is much clearer in other racing formulae, where the cars being raced may be modified versions of commercially-available road cars. Audi, Subaru and Mitsubishi built their reputation for performance almost entirely off the back of the World Rally Championship.

F1 is the pinnacle of motorsports, it's the most expensive racing series out there and one of the most advanced. Every team builds designs and builds their own cars and has new models for every season and then throughout the season they work hard and spend untold millions and man hours improving the cars.

A lot of the fan base is really engaged in the technology race while others are engaged in the personalities, that is what makes the sport so popular as it has a lot of entertainment to offer outside of what actually happens on the track.

People watch F1 for different reasons.

Some people love the crashes, others love the personalities.

Me? I love the racing, the personalities, but most of all I love all the technical developments on the cars. These are fragile prototype cars with state-of-the-art engines (approaching 50% efficiency, which is insane) - new car launch time in F1 just before winter testing is one of my favourites!