Audi’s Innovation Towards Making V6 TDI Engine Compatible with hydrotreated Vegetable Oil

 

When you hear the term of low emissions diesel engines might not be the first thing you think of, but Audi is on the mission to change that and to change the internal combustion engine alive a little longer. Audi has approved its some of their V6 diesel engines to run on vegetable oil. It’s a biofuel called hydrotreated vegetable oil. They consider that it will in a 70 to 90 percent reduction in Co2 emission. Its not quite that simple.

Diesel is quite different from petrol as it’s thicker, less refined, less volatile and its vapors is less combustible. Regular desile oil that you get from supermarket is much thicker that the regular diesel. So, some car will need the parallel fuel system to heat the oil in order to thin it down in cold temperatures. Old diesels that have less refined diesel engines can handle using vegetable oil a lot easier, but many modern systems won’t take it well without modifications. It also contains more glycerin and absorbs more water which doesn’t do good in the modern car fuel system. People who use waste vegetable oil usually have to remove any water and filter it properly before it is used.

Audi’s use of HVO isn’t quite the same as just filling your car with plain old vegetable oil. It’s a renewable biodiesel which made of waste cooking oil and agricultural residue. The Hydro treated part in the name refers to the process where oil reacts with hydrogen, they will then either break it down into hydrocarbons or abb more hydrogen. The result is renewable fuel that can be mixed with diesel or used all on its own its slightly more refined and complex process compared to the regular biodiesel which normally uses a combination of soybean oil animal fats and recycled cooking oil to make renewable diesel replacement because of that Hydrotreated process HVO is deemed to be the cleanest biodiesel of them all. Diesel engine running on regular fuel can really struggle when temperature drops below zero. They rely on the heat for the combustion process, so they use set of glow plugs to heat the combustion chambre. A huge positive for HVO is that it is considerably better in cold conditions. This is rated with something called CFPPP rating the cold filter plugging point is the lowest temperature a particular amount of file can pass through a filter in 60 seconds. Regular diesel is rated at about minus (-15) degrees. But HVO is rated up to an incredible minus (-50). It also has a much better seating rating than the regular diesel. This is essentially the equivalent to an octane rating for petrol and refers to how clean the fuel burns. HVO manages to use burn 30% cleaner than the regular diesel.

Audi has said that it will be compatible with its V6 TDI engines, built from February and March 2022 with the models ranging from the A4 all the way up to A8 and Q8. A lot of its newer four-Cylinder diesel engines were already approved back in 2021. The VAG group has a thing for sharing chassis and the engines across multiple manufacturers. This fuel has also been used approved for the use in V6 diesel Volkswagen tour egg. Audi have specified that it will only be useable on cars with power rated at a maximum of 282 horsepower so it will be interesting to know why they don’t think its suitable for more powerful diesel like the S6 and the S7. It all sounds like positive news for diesel combustion engine