How Much Electric is in Hybrid?

BMW-i8-GeitmannAre cars like the BMW i8 electric vehicles? A question hotly debated by many stakeholders in the electric transportation industry, not least since the government has planned to introduce various incentives for these types of vehicles. The German Electric Mobility Act (EmoG) passed in June 2015 says that communities can allow electric cars on bus lanes – whether or not the vehicles in question are actually running on gas or electricity while driving on there. Parking spaces near charge points can also be reserved for electric cars without the drivers having to use electricity to get to them. To illustrate the issue with an example, H2-international took a closer look at a BMW i8 to determine how much a hybrid car actually relies on gas or electricity.

The i8 is an eye-catcher – without a doubt. No matter where you drive, the eyes of people walking by will follow you. The sports car leaves a lasting impression, especially with the younger generation. As soon as you park it somewhere, you’ll find them gathering around, gazing at the car. Sometimes, when the electric speeder has to stop at a red light, people nearby will spontaneously snap pictures with their smartphones. And the car is sparking emotions: The responses range from dropping jaws to surprised faces and sudden public displays of affection.

But as we all know, looks are only half the package. What lies beneath the well-designed carbon exterior?

Visionary design
The interior of the i8, for whose standard version Germans need to fork out around EUR 130,000 (incl. battery), has a design similar to the outside of the car: stylish, with colors matching the exterior, a digital display and curvy lines in black, grey and blue. The sports mode, however, will change the display color from a chilly blue to an aggressive red. While driver and co-driver sit low but comfortable in the front, the back is much more crammed and not made for people of average height. The scissor doors swing open and close very smoothly thanks to the lightweight CFRP (carbon-fiber-reinforced polymer) aluminum structure.

But infinitely more interesting than the “visionary interior design” (quote from BMW) of the 2+2 seater is what’s hidden under the hood of the plug-in hybrid: a three-cylinder combustion engine (displacement: 1.5 liters) with TwinPower Turbo technology. It offers an output of 170 kW (maximum torque: 320 Nm) and powers the rear wheels through a six-speed automatic. Additionally, the car incorporates a hybrid synchronous electric motor (96 kW, 250 Nm) powering the front wheels through a two-speed automatic. Electricity is stored in a high-voltage lithium-ion battery (7.1 kWh) located in the middle of the underbody.

BMW-i8-IMG_3752Altogether, the hybrid power train “makes the driver aware of the sporty temperament of the BMW i8 at all times,” as the Bavarian manufacturer puts it. Combustion and electric engine accelerate the vehicle (weight: 1.5 tons) and its passengers from 0-100 kph in 4.4 seconds – not only on paper, but on the road too. The company’s i8 press release informs that the car “has an electronically controlled top speed of 250 km/h (155 mph), which can be reached and maintained when the vehicle operates solely on the gasoline engine.”

Bayerische Motoren Werke touts the fact that the car’s high performance is achieved at the “consumption and emission values of a compact car.” Official EU test fuel consumption is said to be 2.1 liters of gas on 100 kilometers, the CO2 value is at 49 g/km (efficiency class A+). Here, at least, theory and reality are far apart, as our road test showed a fuel consumption of 6.7 liters and a power usage of 7.5 kWh per 100 kilometers (combined 66.2 kWh/100 km, i.e., CO2 of 156 g/km) – although, admittedly, the road test was not an eco-ride. The difference in consumption can be explained by the fact that sometimes it is not made clear that the power used has to be added to the gas needed (see box) and that on the road, the car will consume much more energy than in a lab environment (see current public debate).

Only half the story
The Munich-based manufacturer says in its international press release:
“The sprint from 0 to 100 km/h (62 mph) takes just 4.4 seconds, yet combined fuel consumption – as calculated in the EU test cycle for plug-in hybrid vehicles – stands at 2.1 liters per 100 kilometers (approx. 135 mpg imp) plus 11.9 kWh of electricity. This equates to CO2 emissions of 49 grams per kilometre.”
This means that the specification of 2.1 liters per 100 kilometers is only half the story and cannot be duplicated under real-world conditions. Even the manufacturer knows that and adds:
“If the daily commute is combined with longer sections of motorway and country driving – on weekend trips for instance – the intelligent powertrain management in the BMW i8 is capable of keeping consumption below the seven litres per 100 kilometres mark (40.4 mpg imp). And even when [the car] is just being used for long-distance holiday driving, fuel consumption still averages below eight litres per 100 kilometres (35.3 mpg imp).”
BMW also states:
“The process for calculating the average fuel consumption of plug-in hybrid vehicles in the EU test cycle also takes into account the use of the available energy capacity in a fully charged battery.”
This means:
“This figure is based on a driving profile where the high-voltage battery’s capacity is initially used for all-electric driving, before switching to hybrid mode when energy is recuperated to recharge the battery, allowing further sections of the journey to be covered solely on electric power. This profile uses up 11.9 kWh of electricity and 2.1 litres (0.5 gallons) of fuel to complete the 100 kilometres (62 miles).”

BMW, however, seems to base its calculations on the assumption that the power for the car will be generated using renewable energies alone, as the emission values stated only consider the CO2 emitted by the gas consumed. The environmental balance is much worse whenever the car is charged by using household electricity generated by coal plants.

Entirely oversized
The vehicle dynamics of such a sports car are indeed impressive – especially for someone used to driving a station wagon or a compact car. Acceleration, roadholding and handling have been tuned to perfection, so that it is often tempting just to step on the gas and speed through the countryside – the combustion engine has just the right sound for this kind of experience.

A quiet and emission-free electric car: That surely isn’t an accurate description of the BMW i8. Anyhow, the official figures confirm purely electric driving to be only possible up to 37 kilometers down the road and only at limited speed (< 120 kph or 75 mph). Normal operation (Comfort mode) is said to offer a mileage of up to 600 kilometers; the sports mode (incl. boost function) accordingly lower numbers. Despite all of the above, the i8 is an electric vehicle in the eyes of the law, even more so in terms of the new Electric Mobility Act: According to EmoG, plug-in hybrids enjoy the same benefits as other electric cars, as long as they do not emit more than 50 grams of CO2 per kilometer or can at least run 30 kilometers on electricity only.

In brief, the BMW i8 seems mainly to satisfy the expectations of the traditional motorsports fan base. What makes it all the more confusing is that so many i8 models are sold to customers abroad, despite Germany being the only country without a speed limit on its highways. But wherever someone gets into an i8, you can be sure it’s all about the fun of driving – the electric-only mode will likely be a rarely encountered scenario. And regular visits to an available charge point may be rather the exception than the rule. Most of the time, the car runs on gas, which means labeling it an “electric car” is misleading and elevates it above other gas-driven cars, a position that the i8 obviously doesn’t deserve.

Still, the good news for the Bavarian carmaker should be that this model combined with current legislation will be a big help in complying with emission regulations for new cars.

Off, overseas
The BMW i8 is produced in a factory in Leipzig, but demand – especially from abroad – outmatches supply at the moment. Daily output of the hall in Saxony is 20 electric sports cars and 100 i3. BMW’s Head of Development, Klaus Fröhlich, explained: “Customers are currently waiting on an i8 for about a good half year.”
It’s self-explanatory that the Bavarian carmaker has been focusing its sales activities on markets whose governments incentivize electric transportation – the currently bestselling BMW in Norway is the i3. Last September alone, the carmaker sold 1,710 i3 on the US market – as many as never before. The BMW i8 was sold to 182 stateside customers. Germany was never one of the lead markets, according to Fröhlich.

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