We start with what each abbreviation means. FSI comes from “fuel stratified injection”, TSI means “turbo stratified injection” and TFSI means “turbo fuel stratified injection”.
I don’t think we have to say that these 3 engines are on gasoline and that they come from the VAG group. FSI has brought a new fuel system to the market, if until FSI the fuel was sprayed in the intake manifold, the new technology came with a system that sprays gasoline directly into the combustion chamber.
By doing this, FSI, TSI or TFSI engines are more efficient in terms of fuel consumption, achieve higher performance and have better dynamics than conventional engines.
If you like the numbers or you are just curious, 14.7 kg of air or the equivalent of 12400 liters are burned per kilogram of injected petrol.
All of this comes with a downside though. Much less air is added to conventional 1 liter gasoline engines, the FSI improving the mixture has “succeeded” and increasing carbon emissions considerably.
Because of this, the VAG group was not successful with these engines in the USA, because their gasoline contains a lot of sulfur that destroys the catalysts and automatically people stopped buying FSI, TSI or TFSI engines.
The TFSI is an FSI to which a turbine is added. Due to the rich mixture of air and low fuel, FSI technology has managed to solve a big problem of the old turbo engines.
Old cars with turbo technology suffered from spontaneous ignition/combustion of gasoline inside the cylinder, long before this was required according to the operating parameters of the engine. The turbine “managed” to heat the air very hard and to create hot spots inside the cylinder that ignited spontaneously and totally uncontrollable gasoline.
With the advent of TFSI this phenomenon disappeared. The TFSI has brought to market an engine with a high compression ratio, very high thermodynamic efficiency and low fuel consumption.
FSI engine
It is a gasoline engine with direct injection, more precisely the fuel is sprayed directly into the combustion chambers. This technology is better thermodynamically and improves engine efficiency. FSI engines improve engine performance and have better dynamics. Whether they have 4, 5, 6, 8, 10 or 12 cylinders, all AUDI petrol engines use the FSI system today.
Similarities between FSI and TSI
- Cylindrical capacity: 1984cc;
- Maximum power in horsepower: 200;
- Maximum torque: 206 Nm;
- Valves per cylinder: 4;
- Cylinder diameter (measured inside): 82.5mm;
- Cylinder height (measured inside) or maximum stroke of the piston: 92.8mm;
- Cylinder ignition order: 1-3-4-2.
What are the differences between TSI and FSI?
- Timing chain versus timing belt;
- 9.6: 1 compression ratio compared to 10.5: 1;
- Bosch MED 17 engine management compared to Bosch MED9;
- 3 oxygen sensors compared to 2 at FSI;
- The oil is sprayed in the form of jets on the bottom of the pistons to improve their cooling and lubrication;
- A better balanced camshaft;
- Improved fuel supply system;
- Modified piston head;
- Internal parts modified to eliminate parasitic losses;
- Improved PCV system.
- I don’t think it’s very difficult to realize that the TSI engine is an improved and much more efficient FSI.
TFSI engine problems
Older versions of TFSI engines equipped on the A5, A4 and Q5 have a factory error that leads to high oil consumption.
The problem seems to be related to the piston rings that allow small amounts of oil to flow into the cylinders, these amounts of oil burn and so we will have a higher oil consumption. Drivers notice this when the oil level indicator appears on the car.
When the warning light indicates that you need to refill the oil level, you do not need to stop immediately, but you will need to add engine oil shortly. What engines are affected? 2.0 and 1.8 TFSI engines manufactured before 2012, the affected engine codes are CAEB, CDNC and CNDC.
TSI engine problems
TSI engines are the engines that equip most Vw vehicles manufactured between 2008 and 2015. TSI engines are also quite problematic, having problems mainly at the spark plugs but also at the induction coil.
If you have a TSI motor and hear strange engine noises, you may have problems with the PCV valve. Many drivers complained that they had problems with the intake manifold and the fuel pump.
TSI vs TFSI engines
The difference between these engines is a simple one, both work on the same principle only that the TSI engines equip the VW models, while the TFSI engines equip the Audi models.
FSI or MPI? Which is better?
Many of you have probably wondered many times what the difference is between FSI and MPI. The MPI engine has a multipoint injection, compared to TSI engines that have a direct injection, for MPI engines gasoline is sucked from the tank by an electric pump and through the injection ramp is transmitted to the injectors, FSI engines have a different intake manifold than MPI engines.
At the end of the article we would like to present some opinions directly from the owners of such engines.
Golf 5 1.4 FSI owner: “I would drive it non-stop, I really like the way we get along. What I like about it is its reliability, and the engine if it is neat is very quiet and even provides power considering how small it is , I was surprised “.
Owner of the Audi A3 1.4 TFSI: “You need petrol with an octane number of 98, it consumes oil only if you drive 500-700km continuously, I filled it with 150ml at this distance and the suspensions are a bit rigid”.
Golf 6 2.0 TSI owner: “It’s super fast, I’ve ridden a 200-horsepower diesel, but petrol is wow, at the moment I have a problem with an air sensor and it consumes a little more.”
Golf 6 1.2 TSI owner: “I only had minor problems in almost 200,000 km,so I was lucky with it. I only changed the bearings, burned out bulbs, brake pads and things that wear out over time, nothing very expensive or difficult to repair” .
Owner of Audi A5 2.0 TFSi: “The car was pleasant to drive, fun, stable, I could do many activities with it, it was well thought out but the 2.0 TFSI engine was a disappointment. Factory problems with segments, medium to high oil consumption (1l at 1500-2000 km), small weak components (induction coils, pcv valve) From the point of view of reliability we encountered some problems (alternator pulley, front axle arms, wheel bearings, anti-roll bars, valve seals) in -a relatively short time (1 year), which represents a constant stress that I will have to take it back to service “.
Golf 5 1.6 FSI owner: “I feel at ease every day. It’s like riding a bike. I dislike a part of it, the lambda 2 probe with the nox sensor, I changed it. But the problem is that it was expensive in Romania and in Germany I bought it for half price (new) “.
