Back in the eighties and nineties, 'badge delete' was one of BMW's most popular options. A no-cost choice, it offered customers the chance to have their new car supplied without badges informing people what model it was. This course of action was generally beloved of those who had just about scraped together the necessary funds to afford an entry-level BMW. How things have changed. The 520d may be the first rung on the 5 Series diesel ladder, but thanks to the recent addition of 'EfficientDynamics' technology, it's a car that identifies its driver as a clever customer. Badge deletion shouldn't be too popular with this one.

Despite the various minor facelifts that have further softened the angular shape, the styling of the 5 Series still divides opinion. The diesel engine line up, however, is beyond reproach. The 530d acts as the mainstay, with the 535d flagship model offering genuinely scorching performance, while the revised 520d we're looking at here caters for those who appreciate a swift, balanced car but whose budgets don't quiet extend top one of the six cylinder big bangers. Statistically, the bald figures speak for themselves. Roll back the clock not too many years and the 520d's performance figures would have been a credit to a 2.0-litre petrol sportster.

Prices start at £27,190 for the saloon or £29,200 for the Touring estate, but if you like all the bells and whistles, there are M Sport variants priced from over £30,000 for buyers harbouring M5 fantasies. Whichever trim level you opt for, you're getting a package of much improved fundamentals. The four cylinder 1,995cc single-turbocharged diesel has received a useful power hike from 163 to 177bhp, making it now one of the most powerful in its sub-class. Plus it's refined and civilised to boot. The engine's torque comes in long, smooth streams and the engine disguises its turbocharged roots very well, feeling like a bigger normally aspirated unit to drive. The thing that really impresses is how much work has gone into making the car feel suitably premium.

The balance of weighting between the steering and the slick six-speed gearchange, together with the effort required to depress the various pedals is all beautifully judged. The spacing between those pedals, the driving position and the sightlines out of the cabin all lend the belief that the 520d was screwed together by a manufacturer who deeply appreciates the finer aspects of building a car. Drive other rivals and you'll see how quickly they drop the ball in these apparently fundamental regards. Although the 520d isn't massively quick, the engine feels loose and lithe and will punt the car to 60mph in just 8.3 seconds (0.3s faster than before) and on to a top speed of 144mph.

"When you need to blow past a middle lane hog, you'll have instant urge at virtually any point in the rev Range"

The real sweetener is the 55.4mpg economy figure (up from 47.9mpg) that's coupled with a Euro IV compliant emissions rating of 136g/km. This significant improvement on the previous level of 158g/km has seen the car drop equally significantly into Band C for Vehicle Excise Duty, saving the owner further expenditure. Even the versatile Touring estate version tacks a mere 4g/km onto that figure.

How is all this achieved at the same time as an increased does of performance? Well, BMW put it down to what they call their 'EfficientDynamics' technology. This includes a whole host of small but collectively significant features like Brake Energy Regeneration, active aerodynamics, an optimum gear shift indicator and low rolling resistance tyres.

Another jewel in the 5 Series' crown is that these days, all diesel models in the range come with a Diesel Particulate Filter (DPF) as standard for cleaner engine running. A DPF enables diesel-powered BMW cars to surpass the ever-tightening strict pollution-control regulations by limiting the emissions of nitrogen oxides (NOx) and particulates.

If you haven't driven an example of the current generation 5 Series for some time, you might well notice a number of improvements. At the front, the headlights and indicators are clear glass while the kidney grille sits flush with the bumper. The air duct in the rear valance has been revised while the side sill gets an additional contour line and horizontal LEDs are used in the rear light cluster. Inside, the door panels and window switches have been redesigned and there's now eight freely programmable 'favourites' buttons on the dashboard so that drivers don't have to use the infernal iDrive control system quite so much. There's also an optional Lane Departure warning system offered.

Such is the reputation the 5 Series has carved that it is in serious demand as a used vehicle, residual values being extremely strong. Factor that in with low ongoing running costs and you have something that - if you can stomach the upfront price - actually makes a very economical car to run. This is reflected in reasonable leasing costs which have seen it achieve a good deal of popularity. Thanks to the latest tweaks, even the initially surprising styling is starting to bed in quite nicely on this particular eye.

Much thought has gone into the way electronic systems blend with good old manual ones. BMW have taken the notion that electronics should aid rather than replace manual systems and the active steering set-up is a good example. Rather than developing the sort of pure 'drive-by-wire' systems that often isolate the driver from road feedback, BMW has instead developed something that maintains a link between the front wheels and the steering wheel but which adjusts the power assistance dependent upon speed and yaw rate, promising quick turn-in when you punch the 520d into a corner but without the accompanying nervousness at high speed that many such cars demonstrate. This system is networked to the Dynamic Stability Control system, reducing the interventions DSC has to make.

Dynamic Drive, BMW's active suspension system, is available as an option, and Active Cruise Control, a clever set-up that automatically controls distances to the car in front, is also available to order. BMW hasn't left too many safety features out of the 5 Series. Brake Force Display is an interesting concept, enlarging the brake light area when the driver really anchors on. Another first for BMW is Adaptive Headlights - a feature many will associate more with Citroen. This system, sadly still an option, swivels the headlights by up to 15 degrees left and right to illuminate more of the road through a bend. Unlike Citroen's rudimentary old mechanical set-up, this calculates speed, yaw rate and steering angle before steering the beams. Another technology 'borrowed' from another manufacturer - in this case Chevrolet - is a Head-Up Display that projects information onto the windscreen. Again, it's a pricey option.

The BMW 520d is a car that appeals equally strongly to business and private customers alike. With low emissions, strong residual values, low servicing costs and excellent economy, it's one of those cars that once you've overcome the upfront asking price, actually works out to be very affordable to run. It's easy to be attracted by the astonishing 530d and 535d models, but in this case, budget just might be best.

TOP 5 5 SERIES DEALS

The results below show the top 5 SERIES deals on buyacar

	BMW 5 Series 520d SE 4dr [177] Saloon
	ETR	Mthly	Saving £1,568	Price £25,892
	BMW 5 Series 520d M Sport 4dr [177] Saloon
	ETR	Mthly	Saving £1,852	Price £28,728
	BMW 5 Series 520d SE 4dr Step Auto [177] Saloon
	ETR	Mthly	Saving £1,702	Price £27,233
	BMW 5 Series 520d M Sport 4dr Step Auto [177] Saloon
	ETR	Mthly	Saving £1,986	Price £30,069
	BMW 5 Series 520d SE 5dr [177] Touring Estate
	ETR	Mthly	Saving £1,753	Price £27,737