What is the difference between Audi A6 TDI and TFSI engines?

I'm looking to purchase a new Audi A6 and I'm unsure of whether to go for the TDI or TFSI engine. Can you please explain the main differences between the two?

The main difference between the TDI and TFSI engines is the type of fuel they use. TDI stands for Turbocharged Diesel Injection, which means it runs on diesel fuel. TFSI stands for Turbo Fuel Stratified Injection, which uses gasoline. In terms of performance, TFSI engines typically have better acceleration and power, while TDI engines have better fuel efficiency.

Another key difference between TDI and TFSI engines is the way they ignite the fuel. TDI engines use compression ignition, where the fuel is sprayed into the combustion chamber and ignited by the heat of compression. TFSI engines use spark ignition, where a spark plug ignites the fuel in the cylinder. This makes TDI engines better for longer distances and highway driving, while TFSI engines are better for shorter journeys and city driving.

When it comes to maintenance, TDI engines have more complex systems due to the need for a diesel particulate filter (DPF) and AdBlue injection. This can make servicing more costly than TFSI engines. However, TDI engines have a longer lifespan and are generally more reliable in the long run.