With the TFSI badge, you’ll find this on every petrol car that Audi sells, but what does it mean? When it comes to Audi TFSI petrol engines, we’ve got you covered. Whether you're buying a new or used Audi, trying to decipher what Audi's engine codes mean can be challenging. Some car dealerships will clearly mark their cars with the fuel they use, but it can be helpful to know what the manufacturer's shorthand indicates so you can get the Audi engine that you want.

What does TFSI stand for?
TFSI stands for Turbocharged Fuel Stratified Injection and is used to let people know that the engine is a turbocharged petrol unit, combining direct injection of fuel with turbocharging and supercharging, and is a method that Audi was the first auto manufacturer to combine back in 2004, according to Audi Hoffman Estates. Essentially, TFSI is a turbocharged version of the purely atmospheric unit, FSI, which stands for Fuel Stratified Injection. This unit involves fuel being injected directly into the combustion chambers, rather than into the intake manifold in the traditional manner, according to Audi Technology Portal.
Powering a high output and optimum engine response, Audi TFSI engines are up to 15% more efficient. TFSI engines are fantastic for reducing emissions and providing greater fuel efficiency and are available in 4-cylinder, 6-cylinder and V-8 variations. Whereas, FSI engines are known for better dynamics than conventional engines, with better efficiency, and are more favourable in terms of thermodynamics. If you combine the two engines together, they make for an incredible engine inside a sporty, luxury vehicle.
Since autumn 2017, Audi models will often come with a number in front of the TFSI or TDI badge, according to Carbuyer. You'll also find that there will be a number to go alongside these abbreviations, ranging from 25 to 70, and this is used to signify how much power the car has. Audi says that the reason for this number is to allow easier comparison between petrol or diesel and hybrid and electric cars. For example, the smaller the number, the less powerful the engine.
The reason why the German brand has decided to opt for this new naming system is down to the fact that the size of the engine has less bearing on the amount of power it produces than it used to, says Buyacar. A small, yet turbocharged 1.0-litre engine can produce more power than a standard 1.4-litre alternative.
What are Audi TFSI petrol engines?
The truth is, it's more than realistic to see TFSI engines somewhere other than Audi models nowadays, says Apsracingusa, but we still largely associate TFSI engines with Audi more than any other manufacturer.
The TFSI engine has been widely praised over the years for its general overall efficiency and vigorous performance it is able to deliver. The TFSI petrol engine, which uses few cylinders and high technology, is mandatory these days, especially given that Audi is an industry leader, and it needs live up to that standard by providing TFSI petrol engines.
A TFSI petrol engine stands out from the crowd by using an injection system with two modes: one favours fuel economy, and the other strives to offer a performance boost, which means higher mileage and more vigorous acceleration, according to My Car. Repair.

Which Audi Models Have Audi TFSI®?
According to Audi Hoffman Estates, all modern Audi engines use FSI, and nearly every model uses TFSI, including all your favourite Sedans, Coupes, and Crossovers. You can rest assured that no matter which Audi model you pick, whether that be the A3 or the A8, you're going to receive nothing but the best-engineered powertrain possible.
Audi TFSI engine problems
In general, Audi is known for its reliability and in most cases, the Audi TFSI engine has proved reliable but, as with all engines, correct and timely maintenance is the key to longevity, says Carbuyer.
Of course, if you neglect your TFSI engines maintenance, then you might have a lot on your plate, as with any engine, but if you keep up with it, you should be able to try and keep those engine costs over the years down.
When it comes to engine problems, according to My Car. Repair, owners have only reported common problems; nothing that cannot be solved with the execution of timely maintenance tasks.
TFSI vs TSI
If you're a motor enthusiast, then no doubt you're going to be interested in discovering more about the differences between TFSI and TSI.
First things first, did you know that the TFSI and TSI are built using completely different technologies? The TSI engineers did not use some old atmospheric engine as the basis, according to Apsracingusa and the internal combustion engine was developed from scratch.
Having said this, Carbuyer has reported that in newer cars, there tends to not be much difference in terms of the TFSI badge being used and TSI, as the engines are often shared between brands without any changes. For example, it no longer tends to be the case that TFSI engines are being used on belt-driven engines and TSI's for chain-driven engines, even though it used to be on older cars.
The TFSI engine has superiority over TSI, that's obvious by now, because these are motor of larger volume, equipped with a turbine, and is characterised by an impressive service life. Although the TFSI engine might seem better from the outside, with its adequate fuel consumption indicator, the technology is really far from perfect, says Apsracingusa.
The difference between TFSI and TSI is the technology, it's the pistons. The cylinders in the TFSI are smaller, but the area they occupy is larger. Due to this shape, the engine works effectively at low compression. The intake and exhaust were significantly redesigned, and the fuel supply channels were corrected and improved. However, the cost of maintaining this engine doesn't come cheap with expensive oils and filters.
All in all, this may not shock you to find out that TFSI engines are considered to be reliable and qualitative. They live up to their standards, reliable engines with barely any complaints, which sadly isn't something that can be said about TS, according to Apsracingusa.