BMW i3


Debut: 2013
Maker: BMW
Predecessor: No



 Published on 1 Nov 2013 All rights reserved. 


Nissan Leaf, Tesla Model S, Renault Twizy, Zoe and Fluence Z.E., Chevrolet Spark EV, Fiat 500e, Mercedes SLS Electric Drive… there are more and more electric vehicles on the market now, but I think none of them is as revolutionary as this BMW i3. The i3 project, internally known as "Megacity", is a big gamble on EV as well as carbon-fiber technology. It is not just another high-tech showcase like SLS ED or Volkswagen XL1, but a volume model destined to the garages of middle class. BMW reportedly invested some 2 billion euros into this project, and a new production line with annual capacity of 40,000 units has been set up at the Leipzig plant. If it succeeds, it will open up opportunity for a full range of i-cars, fueling BMW with a new (and potentially substantial) stream of new customers. Even if it fails, the EV and carbon-fiber technology it learnt will benefit other BMW models to come in the future.

The brave new marketing of i3 is key to its success. How to sell a car of the size of Ford Fiesta at 2 to 3 times the price? Answer: it has to be very desirable. The green and lightweight technology it used (more on that later) is one reason, equally important is to give it a space-age look and premium quality feel. You think a Renault Zoe look futuristic? Turn to the i3 and you will find the Renault hopelessly conventional. You think the interior of Tesla Model S classy? The BMW compact trumps it easily with Scandinavian-style design and materials. It also uses many recycled and eco-friendly materials to match the green credential of EV. IT addicts will love its simplicity and feel comfortable with its standalone LCD screens. It is designed for new-age people.



It could be difficult to classify the i3. Price-wise, it is about the same as a 328i. Even with government incentives taken into account (for example, £5,000 in the UK and $10,000 in California), it still costs the money of a low-end 3-Series. Size-wise, it sits on the borderline between B and C-segment. Its 4-meter length is very compact, but it is pretty wide at 1775 mm and unusually tall at 1578 mm. This tallness is due to the fact that the battery is located underneath the floor, like most other EVs.

Its chassis is revolutionary. You think Alfa Romeo brave to introduce carbon-fiber chassis to its £45,000 4C? The i3 pushes the entry price down to the level of £30,000, even with a big pack of lithium battery included! Like-wise, its production volume makes it the first truly mass production carbon-fiber car. BMW thought hard how to make it commercially viable. The i3 does not use conventional construction. Its chassis consists of 2 parts: a passenger cell made of carbon-fiber reinforced plastic (called "Life module") houses the cabin and provides passenger protection, while an aluminum-frame lower chassis (called "Drive module") carries all the mechanical and electrical components, including the battery, motor, suspensions and the crash structures. The last one is very important, as it keeps the expensive CFRP passenger cell free of light collisions and saves repair costs. Outside, all body panels bar the roof are made of injection molded glass-fiber reinforced plastic. They can be easily detached and replaced in case of damage, again saving repair costs. The roof is made of recycled CFRP.


To make possible mass production, the production process of i3 is highly automated. Carbon-fiber materials supplied by SGL (in which BMW holds minority stakes) are shipped to Germany where they are turned to laminates and then shaped to individual parts. The Live module consists of 150 such parts. In Leipzig they are bonded together by adhesive using robot arms. BMW developed new techniques to shorten the hardening time greatly, speeding up the assembly. Meanwhile, the aluminum Drive module is assembled at another production line running in parallel to the Live module. They are then bonded and bolted together by robots. Finally, the outer skins are put in place, again by robots. The whole assembly process takes only 20 hours.

Thanks to the state of the art construction, the i3 tips the scale at only 1195 kg, even though the battery alone weighs some 230 kg. It undercuts a Chevrolet Spark EV by 160 kg and Nissan Leaf by a massive 330 kg! It goes without saying that the reduced weight helps boosting performance and mileage. It also means the i3 can use a slightly smaller lithium-ion battery (22 kWh, vs 24 kWh on Nissan Leaf and Fiat 500e) to partly offset the cost of its carbon-fiber/aluminum chassis. BMW quoted a class-leading range of 80-100 miles and a remarkable 0-60 mph time of 6.8 seconds. That's the territory of hot hatches, although top speed is limited to 93 mph to save the battery. The electric motor's remarkable output of 170 hp and 184 lbft also helps it to distinguish from other urban EVs we have seen so far.



To those fearing 80-100 miles range insufficient, they can opt for the range extender, which is actually a twin-cylinder 650 cc BMW motorcycle engine. It is mounted next to the electric motor at the rear axle. Its 34 hp output works solely to generate electricity to power the motor and recharge the battery. This extends the range to 160-186 miles and allows the car to refuel at gas stations, thus the fear for running out of energy is no longer a concern. On the downside, it carries a weight penalty of 120 kilograms thus 0-60 mph is lengthened by 0.7 second.

The i3's rear-engine layout was chosen primarily for packaging benefits, but interestingly, it keeps the traditional values of BMW intact, such as rear-wheel drive and 50:50 weight distribution. A quick, 2.5-turns power steering and suspensions consisting of MacPherson struts up front and five-link axle at the rear also sound very BMW indeed. Unusually, the small car employs very large (19-inch) aluminum wheels but extremely narrow (155/70) tires, which reduce aerodynamic drag yet offer decent traction.



Apart from the design, interior, chassis and propulsion system, the i3 also differs from conventional cars in another area: suicide rear doors. Thanks to the super-stiff carbon-fiber passenger cell, it is able to ditch B-pillars and make possible for Rolls-Royce-style rear-hinged doors. This aids access to the rear seats and adds sense of occasion.

You sit high and upright as in the case of SUVs because the battery is located right underneath the floor. This gives a commanding view on the road. Space up front is generous. Not so good at the rear, as legroom is more Polo than Golf, but the rear bench is wider than a typical B-segment supermini. The cabin feels light and airy. The rear door windows are unusually deep by modern standards, thanks to the step cut into the waist line, but they are fixed in place. The shallow boot accommodates only 200 liters but at least you can fold the rear seats to expand luggage space. The i3 might not be as versatile as conventional hatchbacks, but as a city car it is more than practical enough.



So how does it drive on the road? Pretty good. Acceleration is strong, not only at low speed (as always in the case of most EVs) but also at motorway speed up to 60 mph, then it tails off noticeably. The acceleration is also delivered seamlessly and quietly as you would expect for an EV. The regenerative braking is very well tuned so that in most conditions it doesn't need to trigger the disc brakes. When it does, the brake pedal feels natural.

Putting the battery and all heavy mechanicals under the floor means a low center of gravity, thus the i3 feels remarkably agile and stable to steer. Its small turning circle allows it to be driven and park easily in urban area. The light and direct steering also helps. However, it is not exactly a hot hatch. While the skinny tires offer good traction, they do not produce hot hatch level of lateral grip, thus the car will understeer early in corners. The suspension setup biases towards the firm side, so ride quality is marginal. Aural refinement could be better, as there is a touch too much tire rumble and wind noise allowed to enter the cabin – perhaps because there is no engine noise to mask them. However, if you can forget the double-kidney grille – or if you notice that it is purely cosmetic – and judge the i3 purely as a green urban compact, you will find its driving dynamics quite remarkable. Then consider the upmarket styling, interior and revolutionary technology it employs, you could find it nearly irresistible.

The only question is price. Is it worth the same as a conventional 3-Series? If it is my money, I will put on the latter, but I will enjoy watching my neighbour's i3 and ask him to give me a ride.
Verdict: 
 Published on 7 Dec 2017
All rights reserved. 
i3s


i3s offers stronger performance and cornering prowess, but remains a city car in essence.


The original BMW i3 had a lot to amaze, but one thing it didn't quite match the tradition of BMW is the lack of sporty flavours. This is to be fulfilled by the new variant i3s. From its appearance, you can already tell that it is sportier – the wheels have grown to 20-inch, the tires get much wider and lower profile (175/55 front and 195/50 rear) than the skinny items on the regular model, and the tracks are widened by 40mm to improve cornering stability. The suspensions have been stiffened and lowered by 10mm, while the electric power steering is tuned heavier to match. Outside, you can distinguish it by black wheel arch extensions. The front bumper is also restyled as part of the facelift applied across the range after 4 years of service.

Both the facelifted i3 and i3s get the larger 94Ah (33.2kWh) battery as standard, extending their real-world driving range to about 200km. The rear-mounted electric motor is beefed up slightly, producing 184 hp instead of 170 hp, and 199 lbft of torque instead of 184 lbft. This shortens its 0-60 mph time further to 6.6 seconds, while lifting top speed slightly to 100 mph.

On the road, the new energy can be felt immediately, although the i3 has always been quite brisk in urban driving. Changes to the chassis is noticeable, too. It now controls its body roll more tightly, and the tires deliver much stronger grip in corner. At low-speed maneuvering this improvement is especially evident. However, up the pace and try to drive it like a Ford Fiesta ST, its dynamics start fading out. You will realize that the i3 is still too tall and heavy to be really agile and composed. Although the center of gravity is low, you sit high thus the roll angle is evident and confidence-hurting. Wider they might be, those rubbers still don’t grip as hard as a proper hatchback should, because they are still too skinny in comparison. Note that the front tires are narrower than the rears in order to keep oversteer from happening. You can’t argue with that, because oversteer could be nervous and even dangerous on a rear-engined car. Anyway, it means the i3s understeers and lacks adjustability. Meanwhile, the suspension is stiffened to the extent of borderline firm, lacking the supple quality of Fiesta, or just any good hot hatches.

Make no mistake, the i3s is not a true hot hatch. Just like a Brabus Fortwo or Renault Twingo GT, it offers stronger performance and cornering prowess than its lesser sibling, but it remains a city car in essence.
Verdict:
Specifications





Year
Layout
Chassis

Body
Length / width / height
Wheelbase
Engine
Capacity
Valve gears
Induction
Other engine features
Max power
Max torque
Transmission
Suspension layout

Suspension features
Tires
Kerb weight
Top speed
0-60 mph (sec)
0-100 mph (sec)
i3
2013
Rear-engined, RWD
Carbon-fiber monocoque + aluminum frame
Glass-fiber
3999 / 1775 / 1578 mm
2570 mm
Electric motor
-
-
-
-
170 hp
184 lbft
1-speed
F: strut
R: multi-link
-
155/70R19
1195 kg
93 mph (limited)
6.8 (c) / 6.5*
-
i3 range extender
2013
Rear-engined, RWD
Carbon-fiber monocoque + aluminum frame
Glass-fiber
3999 / 1775 / 1578 mm
2570 mm
Electric motor (generator: inline-2)
(generator: 647 cc)
(generator: DOHC 8 valves)
-
-
170 hp (generator: 34 hp)
184 lbft (generator: 40.5 lbft)
1-speed
F: strut
R: multi-link
-
155/70R19
1315 kg
93 mph (limited)
7.5 (c)
-
i3s
2018
Rear-engined, RWD
Carbon-fiber monocoque + aluminum frame
Glass-fiber
4006 / 1791 / 1590 mm
2570 mm
Electric motor
-
-
-
-
184 hp
199 lbft
1-speed
F: strut
R: multi-link
-
F: 175/55R20; R: 195/50R20
1265 kg
100 mph (limited)
6.6 (c)
-




Performance tested by: *C&D




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