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BMW 420d Coupe Review

The BMW 3 Series Coupe may now be known as the 4 Series Coupe, but with official economy of 60.1mpg, the 420d still promises a compelling mix of efficiency and a rewarding driving experience.

Green Car Guide Rating: 9/10

Key stats

  • Model/Engine size: 420d SE Coupe
  • Fuel: Diesel
  • Fuel economy combined: 60.1mpg


  • Coupe offers a marginally better driving experience than the saloon
  • Excellent official and real-life economy
  • Ideal for company car drivers seeking a sporty-looking car
  • For the ultimate sporty driving experience, you’d have to go for the 435i


The Coupe version of the latest 3 Series Saloon has now arrived, but in order to give it its own identity BMW has called it the 4 Series – in a similar way to Audi naming the A4 coupe the A5. Is the 4 Series sufficiently superior to a 3 Series to warrant a different name?

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Design & Engineering

It will probably be no surprise to learn that despite the different name, the 4 Series shares many things with the 3 Series – which is no bad thing. The key difference is that the 4 Series two-door coupe body is slightly lower and wider than the Saloon, improving the handling. The rear wheel arches are particularly wide, helping to give the 4 Series a purposeful, sporty stance.

The engine is the familiar two-litre TwinPower turbodiesel, and in the case of the test car, mated to a six-speed manual transmission, however an automatic is also available. The diesel engine can sound noisy from the outside of the car, but it generally feels quiet and refined from the inside.

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BMW 420d Coupe Driving Experience

With front engine, rear-wheel drive, perfect 50/50 weight distribution, a lower centre of gravity and a wider track than the saloon, the 4 Series Coupe surely promises one of the best driving experiences for the money. Add in the options of adaptive M Sport suspension and variable sport steering and you’ve got an ideal car to provide enjoyment on A and B roads. If you do lots of motorway driving then the 420d also offers an extremely stable long distance companion, along with high levels of comfort and economy.

The only main area where the 420d is found wanting is in its ultimate responsiveness in environments such as the Scottish Highlands. This is where you really want to be in the 435i to cover ground as quickly as possible whilst enjoying a highly rewarding driving experience. The 435i engine is also extremely well suited to the eight-speed automatic transmission, more so than the six-speed manual box, which can sometimes be a little on the obstructive side.

From the driver’s seat, the 4 Series interior is ergonomically excellent, with everything where you want it – including the large satnav screen, and the superb head-up display, showing information such as speed and satnav directions, being an option that you really should tick.

The four driving mode options of ECO PRO, Comfort, Sport and Sport+ really do give you whatever you want for any situation. Combined with the adaptive M Sport suspension, you can certainly tell the difference in the ride quality between Comfort and Sport.

The only real fault we could find – and it’s a very trivial one at that – was that second gear takes the gear lever very close to the slightly enlarged iDrive controller.

Of course the 4 Series Coupe only has two doors and is a four-seater (although the boot is a reasonable size). If this isn’t practical enough for you then there’s always the 3 Series Saloon, Touring or GT

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BMW 420d Coupe Economy and Emissions

The 420d Coupe with a manual gearbox has an official combined economy figure of 60.1mpg along with emissions of 124g/km CO2. The eight-speed automatic version is more economical with lower emissions, returning 61.4mpg along with emissions of 121g/km CO2.

Our test involved picking the car up from Inverness, driving around Scotland, then down to Manchester, then to Millbrook in Bedford and back, as well as urban driving – over 1000 miles in total. So our 420d experienced virtually every possible driving experience.

Our view is that for a car such as a BMW, economy on the motorway is a crucial test, as this is where most BMWs are likely to be spending much of their time. If you don’t agree with this, see how many BMWs you can count next time you’re on the motorway. We predict that you’ll reach 100 and get bored with this game in a very short timescale. In our tests of BMWs over recent years their real-life economy is generally excellent at motorway speeds, and the 420d Coupe is no exception. During 250 motorway miles from Scotland to Manchester we averaged 56mpg. On A-roads at 60mph we averaged 61mpg. Our overall economy after a week of over 1000 miles of mixed driving was 53.5mpg. This is an impressive result for a car offering the performance, driving dynamics, comfort and quality of the 420d. The various EfficientDynamics technologies on the 420d help with the real-life economy, but we believe that the car’s aerodynamics are a key factor in the high miles per gallon at motorway speeds.

BMW says that every 4 Series engine already meets the forthcoming EU6 emissions regulations.

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Price, Equipment and Model Range

The 420d Coupe, in SE guise as tested, costs £30,795. As usual, the test car came loaded with a range of optional equipment including items such as BMW Professional Media package (£1,990), interior comfort package (electric seats etc) (£1,285), head-up display (£825), adaptive M Sport suspension (£750), metallic paint (£645) and variable sport steering (£250). All the options took the total price to £38,840.

Trim levels for the 4 Series range comprise of SE, Sport, Modern, Luxury and M Sport. Over 50% of buyers are expected to go for the M Sport trim, and that would also be our pick, as it successfully enhances the sporty styling of the car.

There are six engines – the 420i, 428i and 435i make up the petrol range; diesel models are the 420d, 430d, and 435d.

The 420i, 420d and 435d are now available with xDrive, ie. all-wheel drive. For people who want all-year round traction then this option, if complemented by winter tyres, adds a useful extra capability to the 4 Series.

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The BMW 420d Coupe presents a real challenge to us. There’s really not very much wrong with it at all, and it proved extremely economical in real-life use. So it’s ideal for company car buyers who want a more stylish way to travel up and down the nation’s motorways than the 3 Series Saloon, the Touring, or the GT.

However this is a coupe and so there is an expectation of sports car levels of performance. Yes, the 420d performs very well, especially in relation to its economy, but whilst driving around the Scottish Highlands, in the back of your mind you know how incredible the 435i powertrain is. And again, relative to its performance and when compared to what has gone before, the 435i is very efficient.

So… if it’s a company car purchase, with Benefit in Kind considerations and lots of motorway driving, the 420d is probably the one to go for. But if it’s a private purchase, and if you regularly find yourself on some outstanding driver’s roads, then you’ll have a smile on your face a lot more of the time with the 435i. It may not be as green, but this is the best way to get the most out of the 4 Series’ dynamics.

The BMW 420d Coupe therefore scores a Green-Car-Guide rating of 9 out of 10, for being excellent in every way, but not being as much of a rewarding driver’s car as the 435i. We just need BMW to build a coupe with the performance of the 435i and the economy of the 420d – oh, that’ll be the i8 then. Our diary is awaiting a date to drive it.

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Car facts and figures BMW 420d Coupe Review

  • BMW 420d SE Coupe data
  • Fuel economy extra urban: 68.9mpg
  • Fuel economy urban: 48.7mpg
  • Test economy: 53.5 mpg
  • CO2 emissions: 124g/km
  • Green rating: VED band D – first year £0
  • Weight: tbc Kg
  • Company car tax liability (2013/14): 19%
  • Price: £30,795
  • Insurance group: tbc
  • Power: 184 hp
  • Max speed: 149 mph
  • 0-62mph: 7.5 seconds
Paul Clarke

Review by:
Paul Clarke, GreenCarGuide Editor