A plug-in hybrid BMW 3-series has been on the drawing board for some time but since the company’s powertrain engineers have had their hands really rather full with the likes of the i3 and i8 they can be forgiven for a delay in plug-in BMWs becoming reality.
Now set to reach the market in 2016 under the likely badge of a BMW 3-series eDrive, tested here is a relatively far-down-the-line prototype. We drove it at BMW’s Miramas proving ground in France.
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What’s powering the BMW 3-series hybrid?
The conventional engine bit is a familiar four-cylinder turbocharged petrol unit (diesels don’t feature in BMW’s plug-in plans for now) with around 180bhp, sending its power rearward via an eight-speed automatic gearbox. In line with the latter is an electric motor generating a little over 95bhp and 184lb ft.
Under the 3-series' boot floor is a lithium-ion battery pack and a refrigeration pack to keep it cool, packaged well enough to avoid losing usable boot space. The various pieces of the drivetrain puzzle talk to each other via power electronics derived from the i3 and i8 projects'.
Pre-charge the battery through the socket in the left front wing and the zero-emissions electric range in an eDrive BMW is approximately 22 miles. This is important, says the car’s project director Helmuth Wiesler, as ‘most of our customers don’t drive more than 30km (18.6 miles) a day with their vehicles.’
To increase the electric range would mean more weight and more cost, he says, and ‘more than 80% of our customers wouldn’t use the extra range.’ In theory, then, most owners could run the car for weeks without waking the combustion engine.
Why the camouflage on the 3-series eDrive?
By the time the plug-in lands, the current F30-generation 3-series will have been through a mid-life facelift, with a spot of cosmetic surgery front and rear. Hence the swirly stickers, although with X-ray specs donned they appear to be there to underline the fact that this particular car is a future model rather than to mask any secret new styling.
The only visual clue in the interior that this is a part-electric 3-series (apart from the laptop-clutching engineer in our test car’s passenger seat) is the ‘eDrive’ switch next to the gearlever.
BMW 3-series plug-in driving modes explained
Pay attention 007. Like most plug-ins, there’s a collection of driving modes to get to grips with in the new 2016 hybrid 3-series.
Default setting is ‘Auto eDrive’, whereby it’ll stick to electric power until the car reaches 50mph, or you give the throttle pedal a healthy prod, at which point the engine chimes in.
Poking the eDrive button activates ‘Max eDrive’ mode, where the engine won’t butt in for up to an hour, or until 75mph is reached. If you need an extra turn of speed, when filtering onto a slip road for example, pushing the throttle past the kickdown stop brings the engine back into play smartly.
Double-press the same switch for Battery Save mode, preventing the battery from dropping below 50% charge (or if it’s below that level, topping it back up) and ensuring a minimum of four to 12 miles of electric-only driving. Worth a press if you know you’re on the way to an urban area and want to make the most of the electric motor when you get there.
Naturally there’s also a Sport mode, at which point the motor uses its instant torque delivery to give the engine a leg up.
Like the Mercedes S-class plug-in we’ve also sampled recently, the drivetrain can talk to the sat-nav so if a hilly route’s programmed, it’ll use as much of the batteries’ energy as possible on uphill sections because it knows they can be recharged on the way down.
What’s it like to drive?
Smooth. In electric mode the power delivery is quite heavily damped (if anything it wouldn’t suffer from being a bit more abrupt for a smarter take-off) and when the engine cuts in it does so without much of a jolt.
Even so, that’s something that can still be improved, electric powertrain engineer Stefan Prasser tells us from the passenger seat, ‘but that’s software, that’s calibration.’ More effective energy regeneration under deceleration is also on the to-do list before the car’s launch in 2016, he says. No matter how many Post-its are on his desk, the prototype we drove felt well-resolved.
Best news is that it still drives like a 3-series. Weight distribution remains near 50:50 (48% front, 52% rear – similar to a 3-series Touring estate), so it has the same nicely balanced handling. When it’s mustering the last drop of energy from the powertrain in Sport mode it makes quick progress around the Miramas handling course. It doesn’t feel standout rapid by any means, but it’s quick enough.
When the BMW 3-series eDrive does arrive, we’re told it won’t be subject to a price premium over the rest of the model range. Adjusted for equipment, it’s planned to be priced at a similar level to the 328i, which at the moment starts below £30k.
With that in mind, and given that the regular car’s handling and practicality have survived intact, it seems the BMW 3-series plug-in has plenty to bring to the party. Never mind that it’ll show up a little late.
There are more plug-in hybrid BMWs on the way - read Georg Kacher's news of the 2 Series Active Tourer plug-in here.