What is it?
BMW's 5-series with a new generation of four-cylinder diesel engine, offering reduced emissions and reputedly improved consumption.
Pleasingly, the new 'B47' 2.0-litre diesel, which replaces the 'N47', is also more powerful – albeit marginally – than the engine it supersedes. BMW has thusly acquired some cake, and consumed it.
The all-new 'TwinPower' turbocharged diesel, which features a single variable-geometry turbocharger – despite what its name suggests – utilises BMW's latest 'modular' design, entailing a 500cc displacement per cylinder.
Other changes compared to the previous 518d version of the N47 include a higher-pressure common rail injection system, which now operates at 2000 bar as opposed to 1600 bar, and new injectors. These upgrades grant more precise fuel metering and better atomisation, resulting in a more efficient combustion cycle.
There are also myriad other tweaks. At low engine speeds and loads the pump's flow can be throttled back, for example, cutting the power required to drive it and improving overall efficiency.
The net result of all these upgrades is a hike of 7bhp, taking total output to 148bhp. The claimed average economy rises from 62mpg to 64.2mpg, while CO2 emissions drop from 119g/km to 115g/km. Torque remains unchanged however, at 266lb ft.
Fractional gains at best, admittedly, but as VED, company car tax and fuel costs become ever more prominent concerns, and consumers are oft considering downsizing into a smaller car, every little helps in order to maintain the competitiveness of the larger saloons.
Some may be somewhat disappointed to see the new engine retain the rear-mounted and often-problematic timing chain assembly of its predecessor, however; alas the company has had to retain it in order to grant the required bonnet clearance to meet pedestrian crash regulations – which was also the original reason for that design choice. Hopefully, by now, any potential issues have long been engineered out.
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I test drove the A6 Ultra and
I really wanted to like the 2.2d Jaguar XF. Whilst the car had charm, with that engine package it was an embarrassment. Such a world away from the excellent 520d.
I ended up ordering a 330d touring....
RE: 330d
An excellent choice there. Great blend of power and efficiency.
I read the...
RE: Economy
Morning bomb. As mentioned above, I would not like to make absolute judgements based on the supplied test routes and samples – which otherwise took into account a mix of conditions, as stated in the copy, and were driven as the vast majority would drive them. After all, the cars should be tested in a fashion that reflects their intended usage. That is why I suggest those interested take it as a baseline and work upwards, as to avoid any disappointment otherwise. I'm probably preaching to the converted here but we have also found, however, that in some cases lower-output variants can have greater difficulty meeting their claimed averages than their more powerful equivalents. A few years ago I had a 1.6-litre diesel Focus that, on my 60-mile motorway commute, would frequently return 45mpg following a steady 70mph cruise there and back. At one point I tried the same in a 2.0-litre diesel variant, which subsequently returned 50mpg – presumably because it required less effort to sustain the cruise.
RE: big vs small
Well exactly, which makes the comparative lack of performance/£ even harder to stomach. I guess the taxation becomes the saving grace of the low-powered diesel. On the same note I have a 407coupe with the PSA 2.7HDi - on the motorway commute has averaged 41mpg over several thousand miles at 80+mph. Hence my exclamation about the 518.
Lewis Kingston
Thanks for the explanation and taking the time to comment, always appreciated. In your response to another poster you asked about the A6 Ultra, and taking my life in my hands on the Autocar forum, I've had one for a few months now and it's superb. Replacing our family CR-V was a tough act to follow but the clear reduction in running costs combined a large increase in performance and, yes, comfort was amazing.
We never saw any fuel consumption beginning with a '5' in the Honda but it's easy in the Audi. The Avant space and interior quality are just a bonus.
RE: A6 Ultra
So much to add to this
RE: 520d
Morning Pahill. As mentioned in the text the conditions encountered were varied – some motorway cruising, cross-country driving and city driving. I would not like to make absolute judgements regarding economy based on the supplied test routes though, hence why I state you should take 40mpg as a baseline and work upwards. Frequently we find people struggle to meet the claimed averages, so I would not like to mislead people and would prefer instead to give them a sensible starting point. As is usually the case with lower-powered variants, as well, they tend to have to be worked quite hard and consequently that effects the MPG. As you quite rightly observe no-one would spend £66k on a 518d which is why we have focused on a more sensibly priced example in a preferential trim with a few key options. You are indeed correct that the dash is an option though, I will revise that now. Thank you for the heads-up. Have you considered the A6 Ultra at all, out of interest?