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e-Fuel explained: what are synthetic fuels?

There has been a lot of chatter about how synthetic fuels could be the future of petrol and diesel cars, but what really is synthetic fuel and what are the pros cons of eFuels – Rory explains.

Nimisha Jain

Additional words by: Nimisha Jain

Last updated on 30 March 2023 | 0 min read

Synthetic fuels, or e-fuels, have won the internal combustion engine a stay of execution, after the EU, lobbied by Germany's domestic car brands, voted to allow their use in car engines beyond the 2035 cut-off date for new petrol and diesel car sales. But what are they, are they really carbon neutral, can our car engines run on them instead of fossil fuels, and do they mean we might never have to go 100 per cent electric?
Companies such as Porsche and Ferrari are throwing huge investment at the production of e-fuels, or synthetic fuels, because the high-performance nature of their cars requires them to have a low weight, unencumbered by heavy batteries. So another solution that emits no carbon but doesn't use electric technology has long been sought. However, these fuels are expensive to produce and their development is far from the realms of volume manufacture. So what is synthetic fuel, will it really prolong the life of petrol cars, and is this really a solution for a mass-production problem?

What are synthetic fuels?

Synthetic fuels are a carbon-neutral fuel type that can be used in internal combustion engines (ICE).
Carbon dioxide is captured during the manufacturing process (detailed below) and can be used to produce synthetic petrol or diesel and natural gas. If you run the fuel refinery on renewable energy like wind power, you’ve got the ultimate in green fuel, without a battery pack in sight. This means you can theoretically drive your Mustang and reduce the carbon footprint in doing so. The best bit is that this eco-friendly petrol alternative can be dispensed from the existing infrastructure of regular filling stations, so you can refill your car in seconds as opposed to minutes.

How are synthetic fuels made?

Synthetic fuels are made by separating water into its constituent parts of oxygen and hydrogen, via electrolysis.
The hydrogen is then mixed with CO2 to make synthetic methanol, which you can then refine into synthetic petrol or diesel to fuel your existing ICE car in a way that effectively consumes CO2 rather than pumping it into the atmosphere.

Will synthetic fuels replace electric cars?

For now, electric cars are the realistic bet. Processing facilities for synthetic fuels are still expensive and uncommon, and there’s more work to be done for them to widely available at an affordable rate.
Electrolysis, as the name implies, involves a lot of electricity so there needs to be a sustainable and affordable way of generating enough power to meet demand. While electric cars are streets ahead (pun intended), synthetic fuels shouldn’t be written off entirely. Existing fuel-stations can be used to distribute them – meaning the infrastructure is basically there. And, a hybrid running on synthetic fuel could prove a winner on all fronts: cheap to run, fuel efficient and (if renewable energy is used) great for the environment. Watch our full video where Rory dives deeper into whether synthetic fuels could be a better alternative to electric cars.

What’s the downside to synthetic fuels?

Obviously, nothing’s perfect. Creating synthetic fuel needs a lot of energy and, unfortunately, we’re still likely to rely on fossil fuels to make clean fuels unless we can get enough wind, sunshine, waves or whatever it is we plan on getting that power from.
It’s not entirely hopeless: there’s definitely enough guaranteed wind to turn the turbines to power this new facility in Chile, South America. The downside there being it’s Chile, South America, and getting all that synthetic fuel over is going to be tricky at best. There’s no perfect answer. Electric cars are the closest solution, and ongoing innovation and improvement in that area mean a lot of today’s pain points are getting tackled head on, and fast. Synthetic fuels are another solution that could develop over time. And if it helps power legacy vehicles, or vehicles that just can’t run on electricity at this stage, and reduce our impact on the climate? It’s worth investigating.

Why are synthetic fuels being developed?

Companies like Porsche can use initiatives like synthetic fuels to keep their motorsport programme running with a clean conscience, fuel the sports cars you can drive at its experience centres and – ultimately – to sell to the owners of their existing road cars to keep them running, classics included.
Heritage is a big part of many manufacturers’ brands, and rightly so. There have been some incredible cars over the years, and no-one really wants to see them legislated off the roads in decades to come. Synthetic fuels could help keep these great cars running in a greener, cleaner future.
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