Audi has approved many of its models' six-cylinder diesel engines for use with hydrotreated vegetable oil (HVO) as part of the firm’s transition to becoming net climate neutral by 2050.
Since mid-February, selected new Audi models with V6 TDI engines up to and including the firm's range-topping 282bhp unit can be driven on HVO. The models include the Audi A4, Audi A5, Audi A6, Audi A7, Audi A8 and the Q7 and Audi Q8 SUVs.
The Audi Q5 will also gain an HVO-compliant V6 diesel engine at the start of March. It will be followed by the A6 Allroad in the summer, although this model is no longer on sale in the UK. Each HVO-compatible Audi car can be identified by an XTL sticker (for 'X to liquid') on the fuel filler cap. Audi's four-cylinder diesels are already HVO compliant.
Audi claims running one of its vehicles on HVO can reduce CO2 emissions output by 70-95% compared with diesel produced from fossil fuels.
"As the cetane rating of HVO is around 30% higher, the combustibility of the engines is enhanced. The positive effects of this are particularly noticeable when cold starting,” said Matthias Schober, Audi’s head of powertrain development for V-TFSI, TDI and PHEV models.
“We tested the effects on various components, the performance, and exhaust emissions in specific validation runs before granting approval,” he added.
HVO is a type of biofuel. Biofuels are created from renewable resources such as plants, from waste materials such as cooking oil from the food industry or from residues from agriculture.
When combined with hydrogen, they are able to replace fossil components in conventional diesel fuels, or they can be used unmixed as 100% pure fuel.
Oliver Hoffmann, Audi chief development officer, said: "With our Vorsprung 2030 strategy, we're pursuing the clearly defined goal that all new models we launch worldwide as of 2026 will be all-electric only. In this way, we're making an essential contribution on the road to carbon-neutral mobility.
"At the same time, we're optimising our existing combustion engine portfolio for more efficiency and lower emissions. One way we're doing this is by creating the requisite technical foundations for the use of sustainable fuels such as HVO."
Audi plans to produce its last internal combustion car in 2033.
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Sounds great, oil from cooking fuels, then you read also from plants. There's no percentage breakdown of the split but I'd expect very little of it to come from chip fat so all the claim does it make it sound green, just how green is cutting down forests in the amazon to grow fuel crops.