Performance
Audi have recently updated the popular 1,968cc TDI in-line four-cylinder oil-burner and now in the A4 the power output has been ramped up to 177 PS at 4,200 revs, with peak torque of 380 Nm between 1,750-2,500 RPM. This is easily the smoothest and refined motor which can even pass off as a petrol motor. Being mated to a Multitronic CVT, the refined diesel motor offers the most soothing power delivery among the three cars. Since technically there are no gear shifts, the A4 surges ahead very seamlessly. There is no jerkiness, turbo-lag or choppy flow of power, which is surprisingly smooth for a diesel motor. This front-wheel drive sedan sails ahead effortlessly in the most plush and comfortable manner, which is a must-have in the luxury segment. The TDI is hardly audible in the cabin, and all one can hear is a soothing hum from the motor even while cruising past the three-digit mark on the speedo. The engine character is not as sporty as that of the BMW, but the CVT is quick to adapt the right ratios and there’s always enough power on tap. Performance isn’t really a concern either, as the Audi achieves the 0-100 km/h run in a quick 8.91 seconds, and does the quarter mile in a respectable 15.23 seconds at 131.36 km/h. A decent fuel economy of 13.25 km/l on average makes it a very comfortable and practical car available at that price.
There is never a dull moment while driving the BMW 320d, as it has the most dynamic heart in this shootout. Its high-torque 1,995cc TwinPower Turbo diesel engine produces a much higher 184 PS and 380 Nm. The TwinTurbo helps the engine develop maximum torque from as low as 1,250 RPM. However, the motor is not very refined, a shortcoming the BMW compensates with its sensational driving characteristics. The eight-speed automatic transmission shifts gears swiftly and keeps the engine on the boil to make optimum use of its strengths. During city limit speeds the engine noise is clearly heard in the cabin even with the windows up, however as the speed increases, it starts to sound more like a growl which most enthusiasts would relish. The other thing they will love is the strong performance of the 2.0-litre diesel motor. Thanks to the torque converter type transmission it takes just 8.03 seconds to sprint from 0 to 100 km/h, making it the fastest of the three. With a quarter mile timing of 15.77 seconds driving at 143.1 km/h and an equally impressive mid-range with the best average fuel economy of 13.5 km/l the BMW 320d makes a strong case for itself. It is clearly tuned for a sporty drive, and might come across to be on the extreme side for those who have comfort and refinement as their priority. You can feel every gear shift and the powerful thrust throws you back into the seat, a trait enthusiasts will surely enjoy, but the same might get overbearing for people looking for a more relaxed commute.
Let’s move on to the Mercedes-Benz C220 CDI, which has the biggest but least powerful motor under the hood in this lot. Its 2,143cc engine has a rated output of 170 PS between 3,000 and 4,200 RPM and a massive 400 Nm of torque from 1,400 to 2,800 revs. Having said that, the 7G-TRONIC PLUS gearbox lets it down with lethargic gear shifts that do not shift as urgently and give it a poor low-end comparatively. Despite being the heaviest at 1,610 kg it manages to keep the promise of ‘AMG-inspired’ tag and offers good top-end power and a decent 0-100 km/h time of 8.49 seconds, which is half a second off the BMW’s. It is also the fastest in the quarter mile run, taking just 14.35 seconds with a terminal speed of 142.78 km/h. An unpleasant surprise is the amount of diesel clatter the 2.2-litre oil-burner emits and poor soundproofing of the cabin. In terms of smoothness and refinement the C220 CDI doesn’t score as high. It is also the least fuel-efficient in this shootout, returning 11.5 km/l on average.
Another important point to consider is engine refinement and cabin noise insulation. The Audi has the most silent engine, compared to the other two cars, which give out a distinct diesel clatter, especially after 3,000 RPM. The Mercedes has the nosiest motor while the BMW has more of road noise infiltrating the cabin. The A4 also has the best cabin insulation that keeps the occupants free of unnecessary road noise.
