At market launch in Europe, the new Audi A4 and A4 Avant will be available with a choice of three TFSI and four TDI engines delivering maximum power of between 110 kW (150 hp) and 200 kW (272 hp). Compared with the previous model, their fuel consumption has been reduced by up to 21 percent (Sedan model), while their power output has increased by up to 25 percent.
All engines comply with the Euro 6 emission limits, so that the TDI has been labeled a clean diesel. There is a standard 12-liter tank or an optional 24-liter tank for the required AdBlue additive. The standard, start-stop system has also been further improved and comes with new features to reduce fuel consumption further: When the driver stops at a red light, the engine can already be deactivated below 7 kilometers an hour (4 mph); 3 km/h for the A4 3.0 TDI* with tiptronic (1.9 mph).
The entry-level gasoline engine is the 1.4 TFSI*. The compact four-cylinder with displacement of 1,395 cc, has a maximum output of 110 kW (150 hp) and torque of 250 Nm (184.4 lb-ft) between 1,500 and 3,500 rpm. In combination with the seven-speed S tronic transmission, it accelerates the A4 Avant from 0 to 100 km/h (62.1 mph) in just 8.9 seconds and on to a top speed of 210 km/h (130.5 mph). The corresponding figures for the Sedan are 8.5 seconds and 210 km/h (130.5 mph).
With its aluminum crankcase, the new four-cylinder engine weighs just over 100 kilograms, despite its highly complex technology package. The valve-drive module in the cylinder head is designed to be light and rigid. Below it, the exhaust manifold is integrated into the cylinder head – a key element of efficient thermal management. Like the crankcase, the cylinder head has its own cooling circuit. The entire crankshaft drive has a very low mass and frictional losses.
The turbocharger and its peripherals are optimized in all details to build up boost pressure rapidly. With the mixed-flow turbine wheel, the moment of inertia is low, the electrically operated wastegate works extremely precisely and intercooler integrated into the intake manifold results in short distances for the gas mixture to travel. The common rail system develops an injection pressure of up to 200 bar; the toothed belt for valve timing and auxiliary drive is designed to last for the engine’s lifetime.
High-tech power pack: the 2.0 TFSI
The 2.0 TFSI* with a displacement of 1,984 cc is available in two versions for the Audi A4 and A4 Avant. Its technical refinements are the exhaust manifold integrated into the cylinder head, the rotary-valve model for thermal management, the Audi valve-lift system (AVS) for the outlet valves, the electric wastegate of the turbocharger and the dual fuel injection. In partial load, indirect injection in the inlet manifold supplements the FSI direct injection.
In the high-end version, the 2.0 TFSI delivers 185 kW (252 hp) and torque of 370 Nm (272.9 lb-ft) between 1,600 and 4,500 rpm. This allows sporty driving: The new A4 Avant with quattro drive and seven-speed S tronic sprint from 0 to 100 km/h (0 to 62.1 mph) in 6.0 seconds and has an electronically limited top speed of 250 km/h (155.3 mph). The new A4 Sedan has corresponding figures of 5.8 seconds and 250 km/h.
The second version of the 2.0 TFSI*, the gasoline ultra model, delivers 140 kW (190 hp) and torque of 320 Nm (236 lb-ft) between 1,450 and 4,200 rpm. This also results in very agile performance: 7.5 seconds from 0 to 100 km/h (62.1 mph) and a top speed of 238 km/h (130.5 mph) for the Avant; 7.3 seconds and 240 km/h (130.5 mph) for the Sedan (both with S tronic). NEDC fuel consumption is excellent: The Avant consumes 5.0 liters per 100 kilometers (47 US mpg) and the Sedan 4.8 liters (49 US mpg), equivalent to 114 and 109 grams of CO2 per kilometer (183.5 and 175.4 grams per mile) respectively.
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, customers of new Audi A4 and A4 Avant 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 liters 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.
The bestseller in the A4: the 2.0 TDI
As with the TFSI engines, Audi offers the four-cylinder TDI engines with its displacement of 1,968 cc in two power versions. The first delivers 110 kW (150 hp)* and torque of 320 Nm (236 lb-ft) between 1,500 and 3,250 rpm; the second delivers 140 kW (190 hp)* and torque of 400 Nm (295 lb-ft) between 1,750 and 3,000 rpm. The 2.0 TDI clean diesel features several sophisticated technical solutions – with separate cooling circuits, two balancing shafts in the crankcase, a cylinder-pressure sensor, substantially reduced inner friction and a common-rail fuel injection system with a maximum pressure of 2,000 bar.
Emissions stay low thanks to high- and low-pressure exhaust-gas recirculation and multi-stage exhaust-gas aftertreatment including an SCR system (selective catalytic reduction).
Even the less powerful version with 110 kW ensures high performance: The A4 Avant with seven-speed S tronic and front-wheel drive accelerates from zero to 100 km/h (62.1 mph) in 9.0 seconds and has a top speed of 213 km/h (132.4 mph); the corresponding figures for the A4 Sedan are 8.7 seconds and 219 km/h (136.1 mph).In combination with the manual six-speed transmission, the Avant and the Sedan have fuel consumption of just 4.0 and 3.8 liters per 100 kilometers (58.8 and 61.9 US mpg) and emissions of 104 and 99 grams of CO2 per kilometer (167.4 and 159.3 grams per mile).
Strong propulsion: 2.0 TDI with 140 kW (190 hp)
In the version with 140 kW (190 hp)*, the 2.0 TDI clean diesel is also a highly efficient engine. With it, the new A4 Avant* with seven-speed S tronic and front-wheel drive has NEDC fuel consumption of 4.2 liters per 100 kilometers (56 US mpg) and CO2 emissions of 109 grams per kilometer (175.4 g/mi). The new A4 Sedan* consumes 4.1 l/100 km (57.4 US mpg) and emits 107 g/km of CO2 (172.2 g/mi).The powerful four-cylinder diesel engine also delivers an impressive performance: acceleration from 0 to 100 km/h (62.1 mph) with front-wheel drive and S tronic in 7.9 seconds for the Avant and 7.7 seconds for the Sedan; top speeds of 231 km/h (143.5 mph) and 237 km/h (147.3 mph) respectively.
The two 2.0 TDI engines will also be available as “ultra” versions – 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 (150 hp) has NEDC fuel consumption of just 3.8 liters per 100 kilometers (61.9 US mpg) and CO2 emissions of 99 grams per kilometer (159.3 g/mi); the corresponding A4 ultra* consumes 3.7 l/100 km (63.6 US mpg) and emits 95 g/km CO2 (152.9 g/mi). No competitor in the premium segment has better figures. Another 2.0 TDI engine will be added after the market launch with power output of 90 kW (122 hp).
Efficient, powerful and cultured: the 3.0 TDI
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 3.0 TDI clean diesel with displacement of 2,967 cc is available with power output of 160 kW (218 hp)* of 200 kW (272 hp)*, with the first version following shortly after the start of sale.
The three-liter diesel engine, which weighs only 190 kilograms, incorporates numerous high-tech solutions: particularly complex thermal management, new cylinder heads, substantially reduced friction, a modified chain drive and an electrically adjustable turbocharger that delivers a pressure boost of up to 2.0 bar. The exhaust-gas aftertreatment system is installed directly on the rear of the engine, and its innovative NOx trap catalyst works in conjunction with an SCR-coated diesel-particulate filter.
In the first version, the 3.0 TDI clean diesel delivers 160 kW (218 hp). Its torque of 400 Nm (295 lb-ft) is available from 1,250 to 3.750 rpm. The A4 Avant will have NEDC fuel consumption of just 4.4 liters per 100 kilometers (53.5 US mpg) and emits 114 g/km CO2 (183.5 g/mi). This makes the TDI the world’s most efficient six-cylinder engine.
In the high-end version, the 3.0 TDI clean diesel has a maximum output of 200 kW (272 hp) and delivers 600 Nm (442.5 lb-ft) of torque between 1,500 and 3,000 rpm. It accelerates the A4 Avant like a sports car – in just 5.4 seconds from zero to 100 km/h (62.1 mph) – and easily reaches the electronically limited top speed of 250 km (155.3 mph). However, its NEDC fuel consumption is just 5.1 liters per 100 kilometers (46.1 US mpg) and it emits only 134 grams of CO2 per kilometer (215.7 g/mi). The figures for the A4 Sedan are 5.3 seconds, 250 km/h (155.3 mph), 4.9 liters per 100 kilometers (48 US mpg) and 129 grams of CO2 per kilometer (207.6 g/mi).
The Audi A4 Avant g-tron
The Audi A4 Avant g-tron* is the second model after the A3 Sportback g-tron* that customers can run on compressed natural gas (CNG) or Audi e-gas. Its 2.0 TFSI engines has an output of 125 kW (170 hp) and torque of 270 Nm (199.1 lb-ft).
The tanks for the A4 Avant g-tron are located under the rear of the car. They can hold 19 kilograms (41.9 lb) of gas at a pressure of 200 bar and are particularly light thanks to their novel layout. The inner layer consists of a matrix of gas-proof polyamide, while a second layer of mixed carbon-fiber-reinforced plastic (CFRP) and glass-fiber-reinforced plastic (GFRP) ensures extremely high strength. The third layer made of glass fiber helps visualize any external influences. Epoxy resin is used to bind the fiber materials.
Gas consumption of less than four kilograms per 100 kilometers (8.8 lb per 62.1 miles) in a normal driving cycle means extremely low fuel costs for the customer. With NEDC fuel consumption, the bivalent g-tron model drives up to 500 kilometers (310.7 mi) on natural gas. When the gas left in the tank is less than about 0.6 of a kilogram (1.3 lb), gas pressure, falls below ten bar and the engine management automatically switches over to gasoline operation. This allows an additional range of up to 450 kilometers (279.6 mi).
The A4 Avant g-tron is especially eco-friendly when running on Audi e-gas. Audi is presenting a very sustainable offer here until May 31, 2018: The automaker is offering customers climate-friendly Audi e-gas to power the A4 Avant g-tron* – the fuel offer is included as standard for three years and customers will pay only the regular natural gas price. With this deal, Audi is reducing the CO2 emissions of the g-tron fleet when running on gas by 80 percent**. The green fuel Audi e-gas is what makes this reduction possible for the g-tron models. This fuel is produced using renewable energy from water and CO2 or from organic residual materials like straw and plant clippings. During its production, Audi e-gas thus binds exactly the amount of CO2 as is emitted by the car.
Among other things, the brand produces e-gas in its own power-to-gas plant in Werlte, located in Lower Saxony. The process: Three electrolyzers powered primarily by surplus green electricity split water into oxygen and hydrogen.
In the subsequent methanation process, the hydrogen reacts with CO₂. The result: Synthetic methane – Audi e-gas – is created. This is fed into the European gas grid and compensates for the volume of natural gas used by the g-tron model in the New European Driving Cycle (NEDC).
Customers can fill up their g-tron model at any CNG filling station and pay the regular price. By feeding the computed volume of Audi e-gas into the natural gas grid, Audi works behind the scenes to ensure the green benefits of the program, including the corresponding reduction in CO2 emissions. A fuel card is no longer used as the accounting tool. Instead, Audi computes the volume automatically based on surveys and service data from the cars. TÜV Süd, a German testing and certification corporation, monitors and certifies the process. Audi g-tron customers receive a document that confirms their car will be supplied with Audi e-gas and informs them about the certification.
*The fuel consumption and CO2 emission figures of all models named above and available on the German market can be found in the list on the last page of this basic information.