Which Audi A4 is better: diesel or petrol?

By Farzana Chaumoo

We breakdown the engines in the Audi A4 range.

 

TFSI engines

The first entry is the 1.4 TFSI. This compact four-cylinder engine with maximum power of 110 kW and maximum torque of 250 Nm accelerates the A4 Sedan from 0 to 100 km/h in 8.5 seconds and reaches a top speed of up to 210 km/h. Thanks to the aluminium crankcase the engine’s weight is just over 100 kilograms.

The 2.0 TFSI is available in two versions: The top version offers maximum power of 185 kW and maximum torque of 370 Nm. With this engine, the Audi A4 Sedan accelerates from 0 to 100 km/h in 5.8 seconds and its electronically limited top speed is 250 km/h.

The second version of the 2.0 TFSI delivers maximum power of 140 kW and maximum torque of 320 Nm. This also results in very agile performance: 7.5 seconds from 0 to 100 km/h and a top speed of 238 km/h.

 

TDI engines

The TDI engines start with the 2.0 TDI, which is available in two performance versions: 110 kW with torque of 320 Nm and 140 kW with torque of 400 Nm. The driving performance is impressive even with 110 kW. The Audi A4 Saloon accelerates from standstill to the 100 km/h benchmark in 8.7 seconds and can reach speeds up to 219 km/h. With the 140 kW version, the A4 Sedan races from 0 to 100 km/h in 7.7 seconds and has a top speed of 237 km/h.

The two 2.0 TDI engines will also be available as “ultra” engine variants – a badge that signifies the most efficient version of each model series. Modifications to the transmission ratio, bodywork and suspension, as well as the use of tires with optimized roll resistance reduce fuel consumption even further. The A4 Avant ultra with manual transmission and 110 kW has NEDC fuel consumption of just 3.8 l/100 km and emits 99 g/km CO2.

The two six-cylinder TDI engines in the new A4 family are highly distinctive. They combine superior power with the utmost smoothness and efficiency. The two versions are 160 kW and 200 kW. The first variant, the 3.0 TDI clean diesel delivers 160 kW and torque of 400 Nm which is available from 1,250 to 3,750 rpm.

In the high-end version, the 3.0 TDI clean diesel has a maximum output of 200 kW and delivers 600 Nm of torque between 1,500 and 3,000 rpm. It takes a mere 5.3 seconds to accelerate the A4 Sedan from 0 to 100 km/h and reaches a top speed of up to 250 km/h. Its NEDC fuel consumption is just 5.1 l/100 km and it emits only 134 g/km of CO2.

 

Take a look at 2016 – present: Audi A4/S4 engine efficiency

 

Revolutionary combustion method

These results are based on a new strategy – Audi continues to develop its successful engine downsizing into rightsizing. The pioneering efficiency of the 2.0 TFSI is the result of an innovative combustion method whereby the comparatively large engine displacement is not a handicap, but a prerequisite.

With a moderate driving style, drivers of the new Audi A4 and A4 Avant can experience the economical advantages of a small engine but do not feel its disadvantages when driving in a more sporty manner.

The new combustion method with shorter compression and longer expansion phases, as well as increased compression, is designed especially for partial load, by far the most common mode of operation. The intake valves close much earlier than usual; in connection with increased pressure in the intake manifold, this reduces throttling losses during aspiration.

Due to the shortened compression phase, the compression ratio was successfully increased from 9.6:1 to 11.7:1. This means that in the compression phase, the engine only has to compress as much gas as a 1.4 TFSI. Also in the expansion phase, in which it fully utilizes its two litres of displacement, it profits from the high compression ratio; the resulting higher level of pressure during combustion further increases the engine’s efficiency.

In order for the fuel-air mixture to swirl sufficiently despite the short intake time, the combustion chambers, piston recesses, intake ducts and turbocharging of the new 2.0 TFSI are specially adapted to the new combustion method. Under higher loads, the Audi valvelift system opens the intake valves later, resulting in a higher charge, which ensures good power and torque delivery. Injection pressure has been increased to 250 bar.

 

Verdict

These are great engines and it’s not possible to take one side. We also can’t tell you whether you should get a diesel or petrol engine as the choice of engine ultimately depends on your monthly running of a car. Both engines have their advantages and disadvantages. However, it’s good to keep in mind that a petrol vehicle offers a smoother driving experience than a diesel variant.

Diesel cars incur a lower running cost whereas petrol cars are low on maintenance. Diesel engines have to face and handle more combustion pressure than a petrol engine, and for this reason, diesel engines need regular check-ups and changing of fluids making them high on maintenance. And since the engine is more combustive, it also generates more noise. But, the diesel variants have better low-end torque as compared to the petrol variants.

If on average you’re travelling more than 1500km a month than consider the diesel variant for its fuel efficiency but if you’re travelling short distances daily that’s under 50 km or doing city driving then a petrol derivative will be better suited for you.

 

 

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