Most Perfect Hybrid Ever Made
Test Drive

Most Perfect Hybrid Ever Made

Most Perfect Hybrid Ever Made

BMW's two-mode hybrid In fact, it was an expression of extremely advanced technology.

Automotive companies often paint pictures of perfection in their press releases, but in practice they cannot predict the course of world events and plan their approach in the most appropriate way. Sometimes changes need to be made on the fly, sometimes quickly, sometimes not quite adequately. Either way, they bring with them an immeasurable experience, and the evolution of BMW's hybrid lineup is a prime example of this. It wanders in different directions until it acquires those clear forms, expressiveness and certain character that it currently possesses.

The process of a significant increase in oil prices, which began at the beginning of the 1993 century and continued rapidly throughout the next decade, surprised many analysts and provoked significant changes in the automotive industry. At the time, BMW already had diesel engines of exceptional performance, but these cars remained a priority in the European market. At the same time, Toyota insisted on its hybrid system, which became more reliable and transitioned to the luxurious Lexus. Since development began in 1997, with the launch of the first Prius in XNUMX and the gradual expansion of Toyota's hybrid lineup, the company hasn't hesitated a second. When oil prices began to rise, the company could finally reap the rewards of its hard work and perseverance. By the way, even now, after the diesel scandal (it remains unclear why Toyota refrains from using larger batteries and replaceable functions). At Toyota, companies like BMW didn't want to hear about it, and many GM bosses like Bob Lutz even scoffed at them.

Global hybrid co-op

There were good reasons for the launch of the BMW Project i in 2007. When it became clear that the rise in oil prices was fast and steady and tested the entire existence of the automotive industry as it was then, many companies changed the way they look at hybrid technology. Among them, BMW, clearly not quite prepared for what is happening. The same can be said about the direct competitor Daimler-Benz, which in the meantime signed an agreement to develop a hybrid system with… GM. Yes, it may sound strange, but in practice GM had the necessary underlying technology because its Allison transmission division had already developed a sophisticated hybrid system for New Flyer buses. In 2005, those in charge at BMW decided to join the merger with BMW and thus began the so-called global hybrid collaboration.

The main work of the engineers of the three companies was the rather complex "downsizing" of the bus system called "Two-Mode Hybrid" - a technology very similar to Toyota's technology with two motor generators and a combined planetary gear, but in practice more. perfect because it had extra planetary gears that added fixed gears to the system. All three companies put in a lot of effort, but in the end, as a result of the teamwork, the BMW ActiveHybrid X6 was born, respectively. Mercedes ML450 Hybrid and Chevrolet Tahoe Hybrid, as well as several variants of the latter from other GM divisions. The BMW model with its powerful eight-cylinder direct-injection biturbo engine has become the most advanced of them.

It soon became clear to Mercedes and BMW that this system would not be the solution in the long run. The complex of factors and reasons for this is probably known only to people from the upper echelons of the two companies, but perhaps the main one is that the complex system was very expensive. In 2011, for example, the Active Hybrid X6 was supposed to cost €103, while the one used for the X000 6i cost "only" €50.

To this day, BMW delicately ignores the issue of the entire dual-mode hybrid odyssey and ignores this fact from its history. Answers range from "alliance with Mercedes and GM only involved development" to "we've gained a lot of experience." Even then, head of research and development, Klaus Draeger, did not go into details and shifted the focus to the fact that the dual-mode system is just one link in many hybrid technologies that his department is working on. On the other hand, all this does not change the significance of the unique technical solution, which in practice has proved to be the most effective so far, and the fact that it did not last long created an additional aura of mysticism around it. Today, only three BMW ActiveHybrid X6s can be found in the vast database of mobile.de.

Active hybrids: what are they?

Even during the preparation of the ActiveHybrid X6, Mercedes and BMW were already moving down a different evolutionary branch for other hybrid models. The accumulated momentum of cooperation led to the joint creation of the first hybrid versions of the S-Class (S400 Hybrid) and the BMW Active Hybrid 7. Both vehicles already had linear-ion batteries, shared Continental electrical components and a parallel architecture with an integrated integrated battery. in the transmission electric motor. After them, the two companies finally embarked on their own path, which led them to the current status quo with significantly higher share of electricity in the drive and the use of plug-in hybrid technology with pure electric drive.

But let's not get ahead of ourselves. At the end of the first decade of the 6th century, BMW and Mercedes still had a different vision of the hybrid drive concept. Already in two modes, Mercedes' hybrid system targets more moderate drivers using a naturally aspirated six-cylinder Atkinson cycle engine, and the same unit was used for the S-Class. On the contrary, BMW considered the hybrid system exotic, which should be used as an additional "incentive" for the engines and not only not worsen the dynamic qualities, but also be a bonus in this respect. In this context, the acronym ActiveHybrid really made sense and the designers added an electric motor to their powerful motors. Both the ActiveHybrid X7 (see box) and the ActiveHybrid 4,4 were powered by a large 407-liter 2009 bhp biturbo engine. And while the electric motor was still only 2013 kW from 01 to 7 production of the F15 Series 3 and still provided decent extra traction when accelerating, in ActiveHybrid 30 (F5) and ActiveHybrid 10 (F306). to a six-cylinder 40 hp turbo engine. the brutal torque of a 5 kW electric motor was added, connected in parallel to an eight-speed gearbox. When accelerating from just over 100 seconds to 1 km / h, both cars showed quite enviable dynamic qualities. A separate question is how long all this can last with batteries with a capacity of about XNUMX kWh.

However, this philosophy clearly did not work, because all three models were not successful in the market. ActiveHybrid Week was discontinued four years later, and ActiveHybrid 5 and 3, introduced in 2011 and 2012, respectively, lived even shorter lives and ceased to exist in 2015. There was also a new philosophy dictated by Project i guidelines, which no longer included brutally powerful gasoline units, but only smaller four-cylinder variants (even for the X5 and Series 7), complemented by much more powerful electric motors, lithium-ion batteries with significant power. large capacity and the ability to travel about 40 km on a purely electric drive. These are the dictates of the times, and for Europe, with its environmental taxes in many European cities, this philosophy was perfect. When the diesel emissions scandal erupted, many companies, including BMW, highlighted these image products created to complement the range.

BMW's two-mode hybrid will remain a unique technology

The ActiveHybrid X6 remains an engineering masterpiece, unfortunately quite expensive. The system offers unparalleled comfort, and the softness of shifting from one mode to another and from one gear to another is even more pleasant than that of ZF's magnificent eight-speed transmission. It includes two engine-generators similar to Toyota's and operates somewhat on its own principle, but has fixed gears - something Toyota has only recently introduced with its multi-stage hybrid. Unfortunately, this nickel-metal hydride battery model weighed 250 kg more than its regular counterpart, despite the lack of active stabilizers and adaptive suspension. On the other hand, powerful power electronics, located under a massive raincoat on the front cover, controlled power flows and mode selection with impeccable precision. Did it all make sense? The answer is absolutely yes. In a real test cycle of automotive motor and sports, including high speeds, the ActiveHybrid X6 showed an incredible fuel consumption of 9,6 liters. When driving in the city, values ​​​​of about 9,0 l / 100 km were possible. This was a real testimonial for the creators of the two-mode hybrid system and the Bavarian designers. However, this is a full-size model of an SUV weighing two and a half tons, with a huge front end and tires with a width of ... 325 millimeters.

Text: Georgy Kolev

Add a comment