Synthetic eFuels get their name from the production process which sees electricity converted into hydrogen before being combined with CO2 to form liquid fuel that can be burned in conventional engines. Companies involved in the development of synthetic eFuels, like Bosch, claim that if renewable electricity is used and the CO2 is captured from the atmosphere, or recaptured during the manufacturing process, then eFuels are fundamentally carbon neutral.
It’s a great promise: conventional cars would continue to live, and automakers wouldn’t have to throw out 100 years worth of research and development invested into the combustion engine.
With more and more automakers committing to an all-electric future and sales of pure EVs and plug-in cars on the rise, there has been a push from oil companies and a few automakers–notably Porsche–for the adoption of synthetic eFuels as an alternative.
The Latest eFuel Study
Amid the rise of EV technology, the promise of synthetic eFuels extending the life of traditional combustion engines has been a beacon of hope among enthusiast communities. Unfortunately, a recent study commissioned by the European NGO, Transport & Environment, would seem to have scuttled those hopes.
If you ask T&E – an organization largely funded by like-minded NGOs – the promise is too good to be true. According to the damning report, the problem with synthetic eFuels isn’t one of provenance, but one of combustion. Burning fuel is still burning fuel, and cars powered by synthetic fuel still emit just as much NOx as those running fossil fuels. Worse though, the study found cars running eFuels emit three times more carbon monoxide and two times the amount of ammonia compared to conventional gasoline. Notably, particle emissions are greatly reduced in the switch. The cost of eFuels was also criticized.
The study appeared to do little to research the carbon neutrality of eFuels.

The results were determined through lab-based tests simulating real-world driving conducted by IFP Energies Nouvelles using a Mercedes A-class hatchback. Because eFuels are a scarce commodity IFPEN had to blend their own batch of synthetic fuel in order to conduct the testing. There is room for variance in the blend, with much still to be learned about the science of synthetic eFuels.
FuelsEurope, a fossil fuel industry lobby group has subsequently accused T&E of cherry-picking the results and skewing the narrative. According to the lobby group, synthetic eFuels are compliant with current Euro 6 emissions targets, as well as meeting the incoming Euro 7 ruleset.
As of right now commercially producing eFuels is less efficient than powering electric vehicles. According to T&E supplying just 10% of new cars with eFuels instead of electrifying them will require 23% more renewable electricity generation in Europe.
While eFuels appear unlikely to stop automakers from eliminating the combustion engine from new cars sold at the moment, die-hard car culture will never be rid of the combustion engine, no matter how hard special interest groups try.
You can already buy a 1,000+ horsepower crate engine that won’t meet emissions anywhere and jam it between whatever frame rails you see fit. Even if eFuels fail to prolong the combustion engine in new cars sold, these synthetic fuels will be a big part of keeping car culture alive for many more years to come.
