Petrol engines

TSI is our pioneering technology for petrol engines. TSI engines are compact, high-powered and use less fuel. TSI technology blends the best of our TDI diesel and FSI (Fuel Stratified Injection) engines.

You enjoy excellent driveability and outstanding fuel economy. Acceleration is instant, whichever gear you're in. So overtaking is safer and you can power smoothly up hills with no delay. TSI technology is available on an increasing number of our cars, from Polo to Sharan.

As responsible car makers we wanted to make our petrol engines even cleaner and more efficient, while still being fun to drive. Our aim was to create engines that used less fuel and produced lower CO2 emissions without sacrificing power.

The solution our engineers came up with was both elegant and ingenious: an engine that combines petrol direct injection and turbocharging, and in some cases twincharging - a turbocharger and a supercharger working together. The TSI engine was born.

The effect is to combine the benefits of both petrol and diesel power units: smooth and quiet on the road, TSI delivers high torque - pulling power - throughout the acceleration range with little discernible turbo lag.

The successful TSI formula combines a number of different elements:

Smaller engines

At the heart of TSI is a smaller engine. It's more efficient, as there is less power loss resulting from friction. It's also lighter, so the engine has less weight to shift in the car.

Direct petrol injection with charging

Direct petrol injection is combined with a turbocharger or charge compression with a turbo and a supercharger (early variant 1.5 TSI Evo engines) working in tandem. This enhances the engine's combustion efficiency so the TSI engine power output is much higher than that of conventional, naturally aspirated engines.

Torque when you want it

On the 1.5 TSI Evo 150PS the engine-driven supercharger operates at lower revs, with the turbocharger - powered by the exhaust gases - joining in as engine speed rises. The supercharger is powered via a belt drive directly from the crankshaft. This provides maximum pulling power on demand, even at very low engine speeds. TSI engines are designed to deliver maximum torque from engine speeds as low as 1,400 rpm. And that has the twin benefit of not only increasing your driving pleasure but also cutting fuel consumption.

We never stop refining our TSI technology. Some of our latest ideas for the 1.5 TSI Evo 150PS include:

More ways to save weight

These range from a lightened cylinder head cover and a weight saving per camshaft to the refined design of the cylinder head itself.

Optimised fuel mixture

A new injector with six fuel bores for electronic direct injection helps achieve this. The injector jets have been realigned to give more efficient distribution of the fuel mixture in the combustion chamber.

Charge-air intercooling

The turbocharger has a water-cooled intercooler with a low-temperature circuit independent of the engine cooling system. As a result we've cut the volume of the charge air system by more than half, allowing a high charge pressure to build up much more quickly. This gives improved dynamics because it reduces the time it takes to achieve maximum charge in the combustion chambers.

International Engine of the Year awards

Our pioneering technology has impressed motoring experts from across the world. Our TSI range has won the 1-litre to 1.4-litre category of the prestigious International Engine of the Year Awards for five years running and was voted the International Engine of the Year and Best Green Engine in 2009.

The jury for this award is made up of 65 motoring journalists from 32 countries. At the 2009 Awards, the jury said:

"Volkswagen not only attained an overall victory, but also won the ‘Best Green Engine' award. This shows that driving fun and fuel efficiency can certainly be unified in one package."

Dr Rüdiger Szengel, Head of Volkswagen Petrol Engine Development, commented on TSI:

"Their combination of reduced displacement, direct injection and intelligent engine boosting enables top dynamic performance while keeping emissions and fuel consumption low. Winning awards in three key categories is really a compliment to our development team. TSI engines are genuine trendsetters."

WhatCar? Car of the Year Awards

WhatCar? has chosen the Golf TSI range as its Small Family Car of the Year for every year from 2009 to 2012, commending it in unambiguous terms: 

"The TSI is punchy, but keeps running costs low. It’s also very smooth, which contributes to the Golf’s exemplary refinement."

ACT is active over an engine speed range between 1,400 and 4,000 rpm and torque outputs between 25 and approx. 100 Nm – a range that covers nearly 70 per cent of all driving states in the EU driving cycle! If the driver presses the accelerator pedal hard, both cylinders begin to work again without a noticeable transition. The high efficiency of the system has no negative effects on smooth running: even with two cylinders the excellently balanced the 1.5 TSI Evo engine of the Golf runs very quietly and with low vibration.

All mechanical switchover processes take place within one-half of a camshaft rotation; depending on engine speed this takes between just 13 and 36 milliseconds. Accompanying interventions in ignition and throttle valve processes smooth the transitions. What’s more, thanks to an accelerator pedal sensor and intelligent monitoring software, the system can also detect irregular driving profiles – such as during a drive through a roundabout or in sporty shifting on a highway. In such cases, cylinder shut-off is deactivated. The driver is aware of whether two or four cylinders are active by a related indicator in the multifunction display between the speedometer and tachometer.

Altogether, the components of active cylinder management weigh just three kilogrammes. Their actuators, the camshafts and their bearing frames are integrated in the cylinder head; two low-friction bearings reduce friction of the shafts. It is only with the TSI concept – petrol direct injection plus turbocharging – that a cylinder deactivation is even conceivable in its form today.

Thanks to an ultra-rigid aluminium die-cast crankcase, the new petrol engines are especially light with a maximum weight of 114 kg. The 1.5 TSI Evo of the new Golf is 22 kg lighter than its counterpart of the previous engine series. The meticulously practised lightweight construction for which Volkswagen is renowned extends to the smallest of details: for example, engine developers reduced the crankshaft main bearing diameter of the 1.5 TSI Evo from 54 to 48 mm; the crankshaft itself was lightened by 20 per cent, while the weight of the connecting rods was even reduced by 25 per cent. The rod bearing pins are hollow bored, and the aluminium pistons (now with flat piston crowns) have also been weight-optimised.

Particular importance was also paid to the whole issue of thermal management. To use optimally the thermal energy of the exhaust in the hot running phase, and to cool it more effectively at high loads, the exhaust manifold of the new engines was integrated in the cylinder head and was provided with its own cooling jacket.

By means of the innovative construction of the exhaust manifold, Volkswagen was also able to use a very narrow single-scroll compressor in turbocharger selection. This also reduced the engine’s weight. In the new engine, the intercooler was integrated in the induction pipe which is made of injection-moulded plastic, allowing significantly accelerated pressure build-up. This has resulted in very responsive downsized engines.

In the new generation of engines, Volkswagen was also able to make further significant reductions in internal friction. Take the example of the overhead camshafts (DOHC): the drive here is not by chain, rather by a single-stage, low-friction toothed belt drive with a 20 mm wide belt and load-reducing profiled belt wheels. Actuation of the valve drive via roller cam followers and an anti-friction bearing for the high loads of the first camshaft bearing also lead to reduced friction resistances.

To ensure that the engine takes up as little mounting space as possible, ancillary components such as the water pump, air conditioning compressor and alternator are screwed directly to the engine and the oil sump without additional brackets, and they are driven by a single-track toothed belt with a permanent tension roller.

Volkswagen recommends a five year change interval for the toothed-belt.

To reduce emissions and fuel consumption further, and to improve torque in the lower rev range, the intake camshaft on the engines was designed to be adjustable over a crankshaft angle range of 50 degrees– on the 1.5 TSI Evo of the new Golf an exhaust camshaft adjuster is added. It permits the desired spread of control times, enabling even more spontaneous response from low revs; at the same time, torque is improved at high revs.

The maximum injection pressure of the new TSI versions (direct fuel injection) is 200 bar. State-of-the-art five-hole injection nozzles deliver up to three individual injections to each of the cylinders via a stainless steel distributor bar with extreme precision. In designing the combustion chamber, Volkswagen also paid particular attention to achieving minimal wetting of the combustion chamber walls with fuel and to optimised flame propagation.