If you thought the BMW 320D was a little on the small side, and wanted something a little bigger, look no further than the BMW 520D, which is the next step up in the latest diesel-powered offerings by BMW Malaysia. If you still want a bigger car, the... [+ click to enlarge] The 520D looks good; try to imagine it without those stickers on its side. The 5-Series carries a more 'executive' image, and is larger than the 3 Series The 520D shares the same engine as the 320D. Driver's cockpit is made for driving pleasure

If you thought the BMW 320D was a little on the small side, and wanted something a little bigger, look no further than the BMW 520D, which is the next step up in the latest diesel-powered offerings by BMW Malaysia. If you still want a bigger car, there is always the BMW 730D, but that is another story. We will talk about the BMW 520D here, although I may be making some comparisons to the 320D from time to time.

The 320D is a great car, and I liked it except for its sports suspension, which, to me, at least, was a little on the harsh side. Mind you, the 320D handled great, and lived up to the BMW promise of a great drive; it just didn’t suit my current taste in terms of ride. A younger person who spends 90 percent of his driving time flying through corners and testing the outer limits of handling would love the 320D, but I figure I would like that 90 percent of my time in a car would be in enjoying the comfort of a luxury ride.

The BMW 520D, fortunately, was put together with a little more sense, as it is more comfortable, being more ‘executive’ in nature, so to speak. I found the ride to be more palatable, and whatever handling compromises the softer suspension may have made was totally imperceptible to me.

In reality, the BMW 520D is what you get if you put the mechanicals of the 320D into a 5 Series BMW. So, just to recap, the BMW 520D has the same 2.0 litre common rail turbo diesel engine, and the same 6-speed automatic gearbox as in the BMW 320D. This is in line with BMW’s philosophy of providing various engine and transmission options in different BMW bodies, providing great flexibilities in terms of choices and options for customers to choose from. This practice has been ongoing for more than two decades, and I always thought that other car makers should think seriously about adopting this practice, especially some of the big boys in Japan.

The 2.0 litre diesel engine that powers both the 3-Series and 5-Series BMW models is a third generation common rail diesel fitted with a variable geometry turbo charger. According to a spokesman from BMW Malaysia, this engine is tuned to run on EURO 2 and EURO 3 diesel, and will run even better if and when we go to EURO 4. In truth, the EURO 4 diesels of the same capacity do make about 10 percent better power, and it is my understanding that some of the European makers already have diesel engines that are more advanced, more clean burning, and are more fuel efficient, waiting on the sidelines. The 520D on test has a claimed fuel consumption of 8.1 litres per 100 kilometres in EU urban cycle, and a combined fuel consumption of 6.1 litres per 100 kilometres in EU combined cycle.

In my road test, with plenty of hard acceleration and jackrabbit starts to ‘test power’, the OBC (Onboard Computer) indicated a fuel consumption of between 8.5 to 10.7 litres per 100 kilometres; at the pump price of RM1.70 per litre, cost of fuel per kilometre works out to be between 14.45 sen and 18.19 sen a kilometre, both very impressive, and real world numbers. If you are a law abiding driver, travelling at regulation speeds along our toll highways, you are likely going to be in a situation where your toll payments are going to be higher than your diesel costs.

Just as an aside, there is talk that a good diesel engine can easily outperform the best hybrid engine of the same capacity, both in terms of fuel economy and power delivery. I am beginning to wonder if we will soon see diesel-hybrid engine combinations – just dreaming, but remembering that it is dreams like this that spur people on to new breakthroughs in technology. More food for thought is the fact that around 80 percent of cars sold in Europe are diesel-powered; my prediction is that once we go EURO 4 diesel, the trend here will be the same.

Fuel prices around the world are around USD 1.00 per litre for petrol, with diesel costing around the same or about 10 percent more, and at these prices, even with the working populace in the developed countries earning much higher incomes, any savings in running costs spread over the ownership period of a car can make a significant impact. Back here at home, we are facing an imminent fuel price increase and the highly possible removal of fuel subsidies; this makes the introduction of EURO 4 diesel even more critical, as this will open the market for more cars with diesel engines.

Now, back to the BMW 520D; in terms of size, the 5-Series is a little longer (+310mm), a little wider (+29mm), and a little taller (+47mm) than the 3-Series. The 5-Series also has a longer wheelbase, which at 2888mm is 122mm longer than that of the 3-Series. In terms of weight, the BMW 520D is only 75 kilograms heavier, and both cars have the same drag coefficient.

Translated to the road, the heavier 5-Series diesel with the same engine and gearbox should be a little slower and a little thirstier in terms of fuel consumption, provided that both cars carry exactly the same weight in terms of driver and/or passengers. In reality, there is really no difference, or if there is, it is inconsequential, where power delivery is concerned. This is due in part to the fact that the design engineers have replaced the 3.152: 1 final drive gear in the 320D with a slightly lowered final drive gear with a gear ratio of 3.231: 1 in the 520D. The result is a gain in mechanical advantage for the 520D drive train to make up for the weight disadvantage, but that is in some part negated by the 18-inch wheels that the 5-Series also has as a standard feature compared to the 17-inch wheels of the 320D. There is also a slight power to weight ratio advantage that the 320D (11.1 kg/kW) enjoys over the 520D (11.7 kg/kW). As a result, the 520D’s claimed zero to 100 km/h acceleration time of 8.4 seconds, is 0.4 seconds slower than the 320D, and the claimed standing quarter time for the 520D is 29.2 seconds, 0.6 seconds slower than the 320D. Driven at normal speeds, you would hardly notice the difference.

The BMW 520D, like the 320D, comes into Malaysia specked up with BMW’s “Sport Suspension” package, a specification no doubt decided upon by a driving enthusiast working in BMW’s headquarters in Cyberjaya. Fortunately, the 520D has, as a standard feature, a self-levelling air suspension arrangement at the rear, and this helps greatly to make the ride a lot more comfortable than that of the 3-Series, which, in my opinion is the saving grace of the 5-Series. Despite the sports suspension, it is heaps more comfortable to ride in, and in my opinion, the handling is not compromised in any way.

Due to the fact that I drove both the BMW cars back to back, I did feel a wee bit of ‘sluggishness’ in the 5-Series compared to the 3-Series, but anyone driving the car in isolation would not notice any difference. With 350 Nm of torque, fully available at any point between 1750 and 3000 rpm, it can out-accelerate just about any other car on the road, and whatever else is said and done, 8.4 seconds from a standing start to 100 km/h is very respectable indeed. Top speed is 226 km/h, 2 km/h slower than the 3-Series diesel.

In the tradition that is 100 percent BMW, the chassis designers have again used tremendous amounts of weight reduction techniques to achieve a 50:50 front/rear weight distribution, or numbers close to it; again, the handling is exemplary, and the BMW 5-Series diesel remains in essence a driver’s car, although in build and size, it leans more towards the business executive user.

All things said and done, the BMW 520D is a great car; great in that it makes perfect sense in terms of performance, ride, and most importantly, fuel economy. Not that it makes any difference to the man or woman who can fork out the RM388k asking price for it, but in the long run, lower fuel prices will make an impact, whether you realize it or not.