14th November 2017

Diesel makes something of a comeback in the race to develop viable and alternative fuels

Last week, a survey of almost 20,000 AA members revealed that a sizeable third of them are seriously contemplating switching from diesel and also petrol over to electric for their next car purchase1. Chargemaster, who will be working in close partnership with the AA, believes that the UK has “passed the tipping point for electric vehicle adoption” and it’s certainly reassuring that additional specialist training and equipment are being provided to enable breakdown patrols to deal with stranded EVs.

Electricity isn’t the be all and end all for cars and other vehicles of the near future, though. Speaking with Top Gear2 at last week’s Tokyo Motor Show, Toyota summed it up nicely by saying that “hydrogen fuel cell vehicles are the ultimate eco car”, an EV being “a better option in compact cars while fuel cells work for larger cars.” Despite their impressive ranges and super-fast recharging times, hydrogen fuel cell vehicles (FCVs) are currently expensive enough to make one’s eyes water, like the Toyota Mirai that costs around £60,000; but prices are expected to fall in line with hybrids by 2025.

The president of automotive minnow Daihatsu agreed3, commenting that “EV is a great match for small cars people use every day to commute and go shopping because it’s easy to charge and maintain.” That’s all very well for a proportion of private motorists, but doesn’t provide much encouragement for company car fleet drivers, many of whom still munch their way through hefty mileages each year and can’t be held back by charging times.

Somewhat ironically, one of VAG’s premium brands thinks it could have a short-term answer – diesel, but not as we know it. “Diesel cars could be saved as Audi creates new ‘clean’ e-diesel fuel”, reads a headline in the Express today4. The German car brand has announced plans to speed up development of a synthetic fuel it has produced called ‘e-diesel’, which pledges zero CO2 emissions just like electric vehicles. What’s more, hydropower renewable energy is even used to create this new kind of carbon neutral diesel. Without going into too much scientific detail, the process of electrolysis is used to split water into hydrogen and oxygen. The latter dissipates into the atmosphere while the former reacts with CO2 from the air, helped along by micro processes and technology to form long-chain hydrocarbon compounds, which are then separated into Audi e-diesel5.

Audi carbon neutral e-diesel

Clean ‘e-diesel’ isn’t something that recent diesel question marks and headlines have spurred Audi to work on, though, as it actually started envisioning such a fuel as early as 2009, with physical work starting in November 2014 when a facility in Dresden-Reick was commissioned6. The National Geographic7 loved the concept of making diesel fuel that “uses rather than emits” carbon dioxide, and the German Federal Minister of Education and Research, Johanna Wanka, poured the very first litres of Audi’s clean e-diesel into her company Audi A8, heralding “synthetic diesel using CO2 a huge success.” Last week’s news does, however, mark the commencement of larger-scale production at a new facility in Switzerland, where 105,000 gallons or more will be made each year8.

Not everyone is jumping up and down with excitement, though, with some voices9 reckoning that ‘Audi making e-diesel from air and water won’t change the car industry’ and labelling it ‘a revolutionary idea, but unfortunately too little, too late.’ Despite many viewing such breakthroughs as akin to proverbially turning water into wine and delivering viable and affordable fuels to keep internal combustion-powered fleets moving, critics rightly point to feasible production quantities of e-diesel being likened to a dribble in comparison to worldwide diesel consumption from the US, China et al.

Maybe Audi should therefore take such cynics’ advice and give up on its pursuit of carbon neutral diesel, but we still can’t help but feel that such efforts are noble and to be commended. After all, few private motorists can afford to buy or lease EVs, and diesel remains the number one fuel source for many fleets. Audi and other marques are admittedly also simultaneously introducing more and more small-capacity petrol and hybrid models, so at a time when manufacturers are passionately developing all manner of alternative or improved fuel sources, the all-options-open approach seems like a sensible and positive one.


1. http://www.businesscar.co.uk/news/2017/one-third-of-aa-members-aim-to-switch-from-diesel-and-petrol-for-next-car
2. https://www.topgear.com/car-news/tokyo-motor-show/toyota-hydrogen-fuel-cells-are-ultimate-eco-car
3. http://www.news18.com/news/auto/2017-tokyo-motor-show-japanese-carmakers-warm-to-electric-vehicles-but-still-hope-for-hydrogen-1557765.html
4. http://www.express.co.uk/life-style/cars/879107/Audi-diesel-cars-fuel-ediesel-clean-fuel
5. http://www.motortrend.com/news/audi-expands-research-synthetic-diesel-fuel/
6. https://www.audi.co.uk/about-audi/latest-news/audi-primes-the-pumps-with-new-synthetic-water-based-e-diesel.html
7. https://news.nationalgeographic.com/energy/2015/04/150428-audi-ediesel-made-from-water-air/
8. https://www.cnbc.com/2017/11/08/audi-expanding-output-of-sustainable-diesel-fuel.html
9. http://www.alphr.com/cars/1000707/reality-check-audi-making-e-diesel-from-air-and-water-won-t-change-the-car-industry