BMW 3 Series eDrive 2016 Review

Audi has a plug-in hybrid A3 on sale already, but BMW should be the first to market with a mid-size premium German sedan when it arrives in 2016. But with only 35km of electric range and a few NVH concerns, it needs some polishing before it will be a world beater. But, then, that’s what prototypes are for…

It looks for all the world to be a normal 3 Series BMW sedan, except it’s wearing swirling black and white camouflage stickers over its nose and tail.

The top-and-tail bikini is there, we’re assured, for photographic impact only. After all, it probably wouldn’t make a great impression to see a bunch of pure white, current-bodied 3 Series BMWs running around a test track, would it?

And they’re running around the test track, at Miramas in southern France, because they're still nearly 18 months away from production.

This is one of BMW’s answers to coming 2020 European emissions laws, with the handy side benefit of attracting electric-car bonus money for buyers in the USA, Scandinavia and a host of other countries in between.

That’s because beneath its skin lies a plug-in hybrid drive system, giving the 3 Series PHEV (which hasn’t got an official name yet, but the smart money’s on eDrive) the ability to cover up to 35km as a pure zero-emission battery-electric car.

BMW development engineer Helmuth Wiesler doesn’t yet want to give out too many details on the car that will future-proof its biggest selling nameplate against emissions taxes, but there are some things we can tell you.

Firstly, at the heart of the plug-in hybrid is its petrol engine. It’s a 2.0-litre, TwinPower four-cylinder petrol motor, codenamed B48, that is a development of what already exists inside the BMW family.

We say “development” because BMW says the four-cylinder now operates at Lambda 1 across an astonishing 90 per cent of its rev range, reducing emissions and increasing its burn efficiency.

Still, BMW wasn’t keen to provide exact numbers on the engine’s individual performance, instead focusing on what it can do in concert with its electrical system, but we can tell you the B48 motor has 132kW and 320Nm of torque.

The car will also run a 5.5kW/h lithium-ion battery pack beneath the boot floor, but even that’s not quite accurate. The quoted 5.5kW/h figure is its net capacity, which means it’s the useful capacity of the battery in between the too-low and too-high-for-safety figures. The full number is 7.6kW/h, but its charge never drops below a set minimum or above a set maximum.

The juice from that 165kg battery gets sent to a torque transformer that sits inside the eight-speed transmission, replacing the conventional torque converter in the same, slightly modified housing.

That means the 70kW electric motor is effectively the electric torque transformer, acting directly on the transmission and it works both putting energy into the input shaft to make the car go and taking it out again under deceleration to recharge the battery.

There’s a water-cooled inverter there, but BMW has gone against the grain to use refrigerated cooling for the battery pack.

It all looks very, very similar to the powertrain in the Concept eDrive X5 from the 2013 Frankfurt motor show and it’s all designed to fit inside anything that sits on the F30 BMW platform, which includes the 4 Series. After all, BMW has to recover its i3 and i8 investments in electrification any way it can.

On the current NEDC combined cycle, that strategy imbues the 3 Series plug-in hybrid with 35km of pure electrical running, giving it a combined cycle figure of 2.1L/100km – less than half a litre better than the ultra-eco sports coupe, the i8.

But there’s more. Combined, the two powerplants deliver 180kW and 400Nm of torque, so the performance is, BMW insists, in line with a “conventionally powered” six-cylinder 3 Series model. That could only mean the 335i, right? Yet its numbers aren’t at that level. Odd to mention it, then…

But, again, there are no numbers to back it up, which is where we have to rely on the experience of its driving feel. Which we, fortunately, have.

There’s nothing particularly difficult about starting the 3 Series plug-in hybrid. It simply starts off the same 'start' button every other 3 Series model uses, mounted just to the side of the steering column.

The B48 four-cylinder engine doesn’t start immediately, though, because the 3 Series plug-in hybrid starts in the electric-only EcoPro mode as its default setting. Assuming, of course, that the battery is toting enough electrical energy to do so.

There’s a Max eDrive mode, which means the car runs on pure electric power, and it does it well. It’s quiet, it’s strong off the line and it’s going to be enough to impress plenty of people. It’s not without its issues, though.

The step-off power doesn’t come in smoothly, with a small pause then a sudden surge in acceleration before it tapers off again.

BMW’s engineer argued this was just software coding that could be fixed in five minutes, but it seemed a slightly deeper issue than that.

Still, it accelerates nicely all the way up to 130km/h, though its punch tapers off above about 70km/h when, realistically, its job will have been done most of the time.

Even then, though, Max eDrive isn’t necessarily all electric. You just have to stomp through the throttle’s détente at the bottom of its travel and the four-cylinder motor will fire up, with the car presuming you’re in some sort of emergency and needing all hands on deck. Or you’ve found an awesome series of corners, which is much the same thing.

Its default setting will deliver a combination of both power systems, with the car deciding when and where you need it. In the unlikely event that you run the full NEDC combined cycle, you’ll find the car using the electric motor for 50 per cent of the time, according to Mr Wiesler.

It can do better than that, too.

“We have a navigation support so if you put in the destination in to the car it will analyse the journey and the slopes and automatically set up the most efficient driving plan,” Mr Wiesler said. “It will insure that you can drive all electric whenever you have to (for green zones, for example) and wherever it’s possible and wherever it’s needed.”

There’s also a Save Battery mode, where the driver can hang on to any residual plugged-in charge because there’s an upcoming area where it’s going to be needed, but the car will also then turn the petrol engine on to charge the battery if it gets to less than 50 per cent charge.

It’s in the Sport mode that the car really shines, though. It’s liveable in the other modes, but at this stage of development it’s nothing special compared to, say, a Volkswagen Golf GTE.

Its main normal advantage is that it’s rear-wheel drive and that the extra weight of the battery means it sits between 51 and 52 per cent of the weight over the rear-end. Therefore it’s even better balanced for quick driving than most regular BMWs.

With all the power sources pulling, the 3 Series plug-in hybrid is quick -- probably just shy of the 328i for straight-line speed. There is a slight issue with the coarseness from the petrol engine, and it doesn’t slide in and out of the powertrain as seamlessly as the Volkswagen’s four-cylinder engine does. Still, it’s more than a year away from production.

The handling isn’t upset by the new bits stuffed inside the bodyshell, either. Yes, it does feel a bit heavier and that weight does feel a touch higher, but it still has a nice flatness to the way the body changes direction and it was taut and predictable with everything we did to it.

It’s particularly calm on longer corners, where the steering weights up nicely in Sport mode and the weight of the battery seems to plant itself on top of the outside rear tyre, squashing it deeply into the ground.

On our short drive (just two laps of BMW’s 4km handling loop), we found it to be a car of promise, with some great points and some question marks.

One is that the range is considerably shorter than the Golf GTE or the Audi A3 e-tron (though both of those 50km pure-electric runners are a size beneath it). The petrol engines in both cars are also smoother and chime in and out of the powertrain more invisibly. And there is no jerkiness to the electric motors of the Volkswagen Group products when the pedal is pushed quickly, where the 3 Series still has a surge here and there.

Some of these things are expected to be ironed out, Mr Wiesler said, and they’re already another few steps ahead of what we were shown. Others, like the electric range, aren’t up for debate because BMW insists it’s enough.

Time will tell, because when Audi’s A4 e-tron arrives in the same year as this car, you can be sure it will run for 50km on its batteries.

2016 BMW plug-in hybrid pricing and specifications:
Price: TBC
Engine: 2.0-litre turbo-petrol four-cylinder
Output: 180kW/400Nm
Transmission: Eight-speed automatic
Fuel: 2.1L/100km
CO2: 50g/km
Safety rating: TBA

What we liked:
>> Strong performance
>> Slick, predictable handling
>> Easy and clear to operate

Not so much:
>> Not seamless in its powertrain transitions
>> Petrol engine is coarser than expected
>> It's still 18 months away