|The Audi A1. Click to enlarge.|
Audi, which has been teasing out details of its upcoming A1 compact to launch this summer, has provided a more detailed overview of the vehicle, including the drivetrain options.
Audi will initially offer the A1 with four engines; the two TFSI gasoline engines and the two TDI diesels cover a power range from 63 kW (86 hp) to 90 kW (122 hp). All of the engines employ direct fuel injection and turbocharging. This downsizing concept coupled with energy recuperation and stop-start technologies from the Audi modular efficiency platform give them fuel consumption ranging from 3.8 to 5.4 liters per 100 km (43.6 to 61.90 mpg US).
The entry-level gasoline engine is the new 1.2 TFSI. It generates 63 kW (86 hp) and produces its peak torque of 160 N·m (118.01 lb-ft) already between 1,500 and 3,500 rpm. Coupled with a five-speed manual transmission, the four-cylinder accelerates the A1 from 0 to 100 km/h in 12.1 seconds on its way to a top speed of 179 km/h (111.2 mph). In the EU driving cycle, it consumes 5.1 liters of fuel per 100 km (46.1 mpg US), which corresponds to 119 grams of CO2/km (191.5 g/mile).
The newly developed four-cylinder exemplifies the Audi’s downsizing strategy of substituting turbocharging for volume. The engine, with two valves per cylinder displaces only 1,197 cc and has been optimized for low weight and low friction. Its cast aluminum crankcase has its own cooling loop separate from the cylinder head. The water in the block is not circulated immediately after the engine is started, enabling the engine to come up to temperature more quickly and shortening the phase of increase frictional resistance due to cold oil.
With 90 kW (122 hp), the 1.4 TFSI offers peak torque of 200 N·m (147.5 lb-ft) continuously available between 1,500 and 4,000 rpm. A turbocharger with a water-cooled intercooler pressurizes the 1,390 cc engine with four valves per cylinder.
Together with the seven-speed S tronic, the 1.4 TFSI gets the A1 up to highway speed in 9.1 seconds. Top speed is 200 km/h (124.3 mph). The standard six-speed manual transmission bumps the time for the sprint to 9.2 seconds, but does not affect top speed. Average fuel consumption is 5.1 and 5.4 liters/ 100 km (43.6 and 46.1 mpg US), respectively, in the EU test cycle.
The power output of the new 1.6 TDI comes from a displacement of 1,598 cc. Internal friction in the compact four-cylinder has been systematically minimized. Audi offers two versions of this engine. The more powerful 1.6 TDI unit produces 77 kW (105 hp) and 250 N·m (184.39 lb-ft) between 1,500 and 2,500 rpm, and is coupled with a five-speed manual transmission. The 16-valve engine accelerates the A1 through the standard sprint in 10.8 seconds before reaching a top speed of 187 km/h (116.2 mph) while consuming an average of 3.9 liters/100 km (60.3 mpg US).
The second version of the 1.6 TDI generates 66 kW (90 hp) and 230 N·m (169.6 lb-ft) of torque between 1,500 and 2,500 rpm. Coupled with the five-speed manual transmission, it accelerates the A1 from 0 to 100 km/h in 12.2 seconds. It reaches a top speed of 179 km/h (111.2 mph) and offers fuel economy of 3.8 liters/100 km (61.9 mpg US), which corresponds to 99 grams of CO2/km (159.3 g/mile).
All four engines in the A1 use a recuperation system with an intelligent voltage controller for the generator to recover energy during the braking and coasting phases and store it temporarily in the battery. The next time the car accelerates, this energy flows back into the on-board electrical system, relieving the load on the generator.
The four engines also come standard with a second technology from the Audi modular efficiency platform: the stop-start system. This turns the engine off when the car is at rest, if the gear selector lever is in neutral and the driver’s foot has left the clutch pedal. Stop-start then turns the engine back on as soon as the clutch pedal is depressed.
The stop-start system also harmonizes with the optional seven-speed S tronic transmission. The Audi dual-clutch transmission combines the convenience of a torque converter transmission with the dynamics and efficiency of a manual transmission. It changes gears within a few hundredths of a second without any perceptible interruption of pulling power, smoothly and very comfortably.
Weighing only around 70 kilograms (154.3 lb), the seven-speed S tronic also helps to save weight. Its two clutches run dry—the elimination of the oil supply further increases the already high efficiency of the transmission. Power is supplied to the electrohydraulic actuator as needed.
The driver can operate the seven-speed S tronic via a selector lever or optional paddles on the steering wheel, as in a sports car. There are also two fully automatic operating modes available. In D mode, the transmission management system operates the engine as often as possible at low speeds to save fuel; in S mode, the driving style is sporty and the engine speeds higher. A hill start assist that holds the A1 when starting on a hill is standard.