BMW, Toyota to co-develop new Z4

Toyota has been in the headlines since the Detroit Auto Show thanks to its gorgeously styled "Vision Gran Turismo" car, the FT-1 concept. This is a car that made the leap from virtual to real world, but will "stay as is," according to one Toyota executive, "just a concept."

While many US-based publications are referring to this coupe as the next generation Supra, one source close to Toyota tells us that the FT-1 has nothing to do with the Toyota-BMW relationship.

"BMW is not involved in the new Supra. I just wanted to make that clear," confirms our insider.

"What I can say is that Toyota is involved in the development of the all-new BMW Z4."

In 2013, both companies conducted a feasibility study into the mid-sized coupe's potential and discussed topics including the type of materials to use and even what powertrain.

The exterior design has not been finalised yet, but our source filled us in on one design direction taken by Toyota.

The coupe you see in this image is an artist's impression of what Toyota's version of the Z4 will look like. And while it's edgy and not that pretty, we can expect some strategic touch-ups by the time the car is due for launch in 2017.

The new coupe will employ a front-engine, rear-drive layout following on from the current Z4. But what is surprising says our insider, is the car's lightweight focus: "This car will use the same lightweight body construction as the i3 and i8."

That means lots of carbon-fibre and aluminium in a car which will incorporate basic body and chassis design by BMW.

"And even with that type of construction, you can expect a sticker price around the same as that of the current Z4. No more than $70,000," adds our source.

This sounds incredible given the cost of carbon-fibre up until recently. But as our insider explains, BMW has teamed up with Germany's SGL to co-develop innovative carbon fiber technology that is seeing the cost of such materials fall significantly -- to less than one-fifth of its current value.

The design and construction of the body will be done by BMW incorporating the latest lightweight technologies used in the i3 and i8. So what is Toyota bringing to the party? One guess: its next generation plug-in hybrid technology.

An advanced interpretation of the current THS II system, the new version will incorporate a capacitor. Like a battery, a capacitor can store electrical energy. But unlike a battery, which can produce electrons through chemical reactions, the capacitor is much simpler as it can't produce electrons.

We have already seen one form of Toyota's next-generation capacitor-using plug-in hybrid system inside the THS-R units fitted to the TS030 Le Mans racing car as well as the Yaris Hybrid R Concept revealed at last year's Frankfurt motor show.

These two early versions point the way to such hybrids being employed in future road cars as the energy density is lower in capacitors (used in conjunction with Lithium-ion batteries) which allows for quicker acceleration. In terms of power storage and delivery, our source suggested we think of the KERS units being used in today's F1 championship.

"It's power storage and acceleration response is very similar to that in the F1 KERS technology.

"We cannot expect to see a Toyota engine fitted here," says our source. "The chances are not zero, but very low. We can however, expect to see Toyota's new hybrid system used."

In fact BMW's engine supply has already begun in earnest. From January 2014 at its plant in Turkey, Toyota has started production of the new Verso, a small Euro-spec MPV powered by a BMW diesel engine.

Toyota is calling the 1.6-litre four-cylinder diesel the "D-4D," in line with its internal naming system but in fact, this 82kW (112hp) engine was supplied by the German carmaker.

"For the new Z4 and its Toyota cousin, the potential for an engine no bigger than a 2.0-litre is very high," says our source. "Add the new Toyota hybrid unit to that 2.0-litre and you have a potent powertrain with superb mileage and clean emissions."

Although the two cars, the next-gen Z4 and the as yet unnamed Toyota variant will employ identical powertrains and plug-in hybrids (with capacitors), the body designs will be quite different.

And the introduction of these cars will herald a new era of markedly cheaper carbon fiber construction that will become widely used in the car industry.

Illustration:  Holiday Auto magazine