Mercedes A-class engine and gearbox
The A-class is powered by the 1.6 liter turbocharged, four cylinder petrol power plant we saw earlier on the B-class. On the A-class with its lighter weight, the engine feels all the more sprightly. With its peak power output rated at 122bhp at 5000 rpm and peak torque of 200 Nm spread between a wide band of 1250-4000 rpm, the A-class has fairly potent mill under its bonnet. The direct injection engine employs piezo injectors and advanced technologies for low friction and better combustion.
Now, 122 bhp may not sound like a lot of power for a premium car, but the torquey engine and the relatively lighter weight of the A 180 ensures that driving it is indeed an enjoyable experience. Weighing well above 1.2 ton with all that engineering and safety aids packed in, the A180 isn’t exactly featherweight. Like most petrol motors, it isn’t quite yummy like a diesel at lower down the rev range. Sure there’s is enough power to keep it trudging along at slow speeds even at a little above 1200 rpm, but that isn’t a pronounced pull.
Past 2000 rpm, the A-class’s engine gets going with some tasty juice beginning to flow. It really comes into its own past 3000 rpm, with the turbo properly spooled and loads of power joining the omnipresent torque to create a heady synergy of thrust. The engine which is slightly gruff in its note gets singing past 4000 rpm with a masculine roar. The powerplant is redlined at 6250 rpm, but you’d do well to shift a little before that to achieve best acceleration as the turbo engine is at its best a little before its peak.
All that technical data comes together for a 0-100km/h sprint time of a little more than 9 seconds. Top speed is rated at more than 200km/h, but as we experienced, with the little engine it takes some time getting there. 160 kmph is attained without much ado, 180 takes a bit of time, beyond which the A-class puffs and pants a bit.
The engine is mated with the latest mainstream transmission in the M-B stable – the 7G-DCT dual clutch transmission. At a length of 367 millimetres and a weight of 86 kilograms, the 7G-DCT is more compact and lighter than the transmissions in this torque class which have been available on the market to date. The transmission is sufficiently quick and comes with shifter pedals behind the steering wheel – great feature for a car in this segment.
With three modes to choose from, and pedal shifters for manual gearshifts, the A-class offers plenty of fun for the driver willing to engage and commit himself. Three gearshift modes are available to the driver:
• ECONOMY: in this mode, the transmission performs gearshifts fully automatically with due regard to a particularly economical style of driving at low revs
• SPORT: the transmission performs gearshifts fully automatically. The shift and response times are shorter, with gearshifts at higher engine speeds
• MANUAL: in this mode, the revs hold on all the way to the redline, or slightly before that, waiting for the driver to shift manually via shift paddles behind the steering wheel.
In ECO or Sport mode, the driver is still able to intervene manually in the gear-shifting process via the shift paddles. The transmission reverts to the selected automatic mode after the paddles have remained inactive for twelve seconds, or after a longer delay when driving downhill or on winding roads.
The car also comes outfitted with an ECO start/stop function which turns the engine off on detecting a halt, and turns it on automatically. Once turned on after the engine being switch off, the B-class will always choose Eco as the default mode.
The 1.6 liter engine on the B-class may not be an absolute hoot, but it still has enough pep to hot things up just right. Combined with the brilliant 7G-DCT tranny, it makes for one spicy, yet delectable recipe.