In Europe, Volkswagen has introduced the new Golf TSI BlueMotion featuring a new 1.0-liter, 3-cylinder with low fuel consumption of 4.3 l/100 km (54.7 mpg US) (99 g/km CO2)—more efficient than any previous Golf with a gasoline engine. (Volkswagen unveiled the model earlier this year at the Geneva show.) The new TSI engine also offers the highest specific torque of any large-scale production series gasoline engines: 200 N·m per liter displacement.
Despite its efficiency, the Golf TSI BlueMotion with the 85 kW / 114 hp downsized 999 cc EA211-series engine reaches 100 km/h in 9.7 seconds and goes on to a top speed of 204 km/h (127 mph). A 6-speed manual or 7-speed DSG (with automatic gear changes) are available; both consume just 4.3 l/100 km.
|The maximum power of the three-cylinder engine—85 kW / 115 PS—lies just above the level of the Mk1 Golf GTI (110 PS from a 4-cylinder, 1.6L engine) introduced in 1975.|
|In terms of responsiveness and top speed, the 204 km/h Golf TSI BlueMotion surpasses the original hot hatch (182 km/h).|
|When it comes to fuel consumption, the new Golf TSI BlueMotion even beats the first diesel-powered Golf TDI BlueMotion (4.5 l/100 km).|
Until now, the Golf BlueMotion was only available in diesel (TDI) and natural gas (TGI) versions. The Golf TSI BlueMotion (which can be ordered in Trendline and Comfortline trim levels) now extends the model range.
The Golf Estate and Golf Sportsvan are also launching TSI BlueMotion models. With a manual gearbox, the Golf Estate also consumes 4.3 l/100 km; with DSG the figure is 4.5 l/100 km (52 mpg). For the Golf Sportsvan, the figures are 4.5 (manual) and 4.6 l/100 km (51 mpg).
The 1.0L TSI overview. Volkswagen engineers set three primary objectives for the development of the 1.0 TSI (85 kW / 115 PS) compared to the already very good 4-cylinder 1.2 TSI (81 kW / 110 PS) with four cylinders: lower weight; reduced CO2 emission; improved driving dynamics.
The weight was reduced by 10 kg (to 89 kg / 196 lbs), and CO2 emissions were reduced by 10%. Torque was increased from 175 N·m to 200 N·m (148 lb-ft).
Another important goal was to attain the lowest possible level of engine noise. Based on the interplay of various internal engine modifications—i.e., without additional insulating materials—the team of engineers implemented acoustics that are on the level of good four-cylinder engines.
Highly advanced basic layout. The Volkswagen EA211 engine series served as the foundation for designing the new 1.0 TSI. EA211 refers to a family of advanced gasoline engines and incorporates both three-cylinder and four-cylinder engines. The EA211 engines made their debut in the small Volkswagen up! and progressively moved into car segments up to that of the Passat. Engine versions with 1.0, 1.2 or 1.4 liters of displacement—with or without turbocharging—are used, depending on the model series.
The engine in the new Golf TSI BlueMotion is the latest three-cylinder engine with turbocharging.
The engine’s maximum torque of 200 Nm is available from a low 2,000 rpm; this figure remains constant up to 3,000 rpm. 200 Nm is considered a top value for a three-cylinder engine. The engine provides 175 N·m (129 lb-ft) of torque to the front axle at just 1,500 rpm—one reason why this engine’s performance is so dynamic.
The turbocharged gasoline engine with its 10.5:1 compression ratio enables both cruising in high gear—thanks to the maximum torque being available at low revs—and quick upshifting from lower gears at higher rev levels. The turbocharged engine develops its maximum power of 85 kW/115 PS between 5,000 and 5,500 rpm.
Crankshaft group has low mass and low friction. The crankshaft group—crankshaft, pistons and connecting rods—is distinguished by low moving masses and low friction. The aluminium pistons and forged connecting rods were weight-optimized such that the 1.0 TSI can do without a balancer shaft. The total weight of the crankshaft was also reduced by 6% by reducing the weight of the crankpins.
Four counterweights reduce internal forces in the crankshaft, which in turn reduces loads on the crankshaft main bearings. Very small-sized yet extremely robust crankshaft main bearings and connecting rod bearings make a significant contribution towards reducing friction in the new engine.
Exhaust manifold integrated in cylinder head. Another very high priority item during the development phase was thermal management. The exhaust manifold of the 1.0 TSI has been fully integrated into the cylinder head (four valves per cylinder) and fitted with a separate cooling jacket to make the best possible use of exhaust gas energy during the warm-up phase and to cool the exhaust gases even more effectively at high loads.
On top of that, Volkswagen engineers designed a dual-loop cooling system. By using an additional thermostat, the coolant temperature in the cylinder crankcase is regulated to a higher level than in the cylinder head. This offers benefits in terms of internal engine friction, which in turn have a positive effect on fuel economy.
Cooling and heating. The base engine is cooled by a high-temperature loop with a mechanically driven coolant pump, while a low-temperature loop, powered by an electric pump, circulates coolant to the intercooler and turbocharger housing as needed. The passenger compartment is heated by the cylinder head circulation loop, so that it warms up quickly like the engine.
Small turbocharger. The design of the exhaust manifold enabled the use of a compact and lightweight single-scroll compressor with an electric wastegate actuator. This wastegate actuator performs the crucial opening and closing of the bypass valve very quickly.
In the low rev range, the bypass valve (also known as a wastegate valve) must be closed in order to drive the turbocharger with the full exhaust gas stream of up to 1,050 ˚C to ensure a consistent build-up of torque. Its maximum charge pressure is 1.6 bar. To reduce losses in the charge changing process in part-load operation, the exhaust backpressure can be reduced by fully opening the wastegate. The engine’s responsiveness is improved, because the wastegate actuator is able to regulate the pressure in the wastegate valve very quickly.
Toothed belt for valve train. Due to its design, internal friction in the small three-cylinder engine of the Golf TSI BlueMotion is already rather low. Moreover, this engine also benefits from the overall innovative design layout of the EA211 engine series and related measures implemented to reduce internal friction.
This not only relates to the crankshaft group, as mentioned above, but also to the valve control and auxiliary drives. The 1.0 TSI is equipped with inlet and exhaust camshaft adjustment; the adjustment range is 50 degrees of crankshaft angle on the inlet side and 40 degrees on the exhaust side.
By taking this approach, the designers of the three-cylinder engine achieve a powerful torque build-up at low engine revs and high power at high revs. The two overhead camshafts are driven by the crankshaft via a toothed timing belt. Compared to a chain drive, it exhibits around 30% less friction. Due to its high-end material specification, this toothed timing belt’s service life reliably spans the entire life of the vehicle. As a result, it is no longer necessary to perform the previously obligatory replacement of the toothed belt as a maintenance item. Overall, the harmonized forces of the toothed belt drive lead to low friction, improved fuel economy and greater durability.
Efficient combustion process. The maximum injection pressure of the 1.0 TSI is relatively high for a gasoline engine at 250 bar. Advanced 5-hole solenoid injectors, which are supplied with fuel from a stainless steel fuel rail, make precise injections into each cylinder with up to three individual injections per cycle. A more efficient combustion process with faster energy conversion is achieved based on the interplay of the injection components with a further developed charge cycle (optimized thermodynamics), in which the air-fuel mixture flows into the combustion chamber extremely rapidly via a tumble channel. Here too, this results in noticeably improved responsiveness and low emission figures.
Compact and efficient. The sum of many minor improvements have made the 1.0 TSI one of the most compact and efficient gasoline engines. As examples: 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 attached directly to the engine and oil sump without additional brackets, and they are driven by a toothed belt running over a permanent tension roller.
In addition, the engine has a map-controlled oil pump that only draws as much power as required at the specific operating point.
Assistance systems and networking. Numerous assistance systems are fitted as standard to the Golf TSI BlueMotion. Optional features include the Blind Spot Monitor with Rear Traffic Alert, DCC adaptive chassis control, Light Assist and Dynamic Light Assist main beam control assistants, driving profile selector, Lane Assist lane departure warning and Park Assist park steering assistant.
The entire line-up of the latest infotainment systems is also available for the Golf TSI BlueMotion, including the online services offered via Volkswagen Car-Net. Other new options are Volkswagen Media Control and App Connect.
The Golf TSI BlueMotion is available in two equipment trim levels: Trendline and Comfortline. In Germany, the Golf TSI BlueMotion Trendline costs €20,450 (US$22,422) and includes standard features such as air conditioning, seven airbags, Automatic Post-Collision Braking System, XDS electronic differential lock, start/stop system with brake energy recovery, model-specific rear spoiler in body color, sport suspension (body is 15 mm lower) and BlueMotion 15-inch “Lyon” wheels.