September 26, 2005 The undeniable trend in world automotive sales over the last few decades has been the rise of the SUV, and in particular, the luxury SUV.The luxury SUV market offers the spaciousness, comfort, technology and customer services of a luxury car without the same price and value-for-money is just one of the reasons why luxury SUVs are increasingly taking the place of the family car. Another key trend of recent times that is gaining strength is the cabriolet – the ability to take the top off a car and drive with the wind in your hair is something people are increasingly prepared to pay for. So why not combine the two trends. German automotive specialist Karmann, best known for the Karmann Ghia Volkswagen, has done just that, and its research suggests the category could be huge within the decade. We agree. We also speak with Jörg Steuernagel, Chief Stylist at Karmann who explains how the idea came about and why the prospects are so bright.
In 1995 Mercedes founded a new niche with the first modern retractable hardtop (RHT) which it developed in collaboration with Karmann. Ten years later RHT models are rolled out by nearly all volume manufacturers or are just about to enter on the market (four big announcements at last week’s Frankfurt Motor Show). Karmann is again setting the trend by proclaiming its new show car is the first Sport Utility Cabrio (SUC). The SUC concept car has a soft top with a separate glass rear window and an innovative chassis system from ZF Friedrichshafen.
The SUC has some unique technical features including doors that open as much as 90 degrees and away from each other, enabling easy egress. The main attraction is the cover and soft top and storage area design because the soft top spans the SUV's occupant and luggage compartments. Because the rear window is not integrated into the soft top, it's comfortable to load luggage when the roof is open.
ZF Friedrichshafen has created a special chassis for effective transfer of power to the 22 inch wheels that also meets the requirements. Via the electronic CDC (Continuous Damping Control) with various parameters an optimal damping level will be reached. The system demonstrates its full efficiency by networking various control elements such as ESP, ABS or CDC. The results are more driving comfort, higher safety reserves and a clear reduction in vibration.
Karmann forecasts that the Sport Utility Cabrio could sell as many as 180,000 units a year within a decade if the automotive manufacturers introduced the design in Western Europe and the USA.
Classic vehicle models, such as sedans and station wagons are increasingly threatened by new niche models. Vans, Mini-Vans, Convertibles, Coupés, Retractable Hardtop-Cabrios, Sport Utility Vehicles and many other varieties make the borders blurred. So, how do designers and engineers find new niches? At the beginning of the Sport Utility Cabrio the idea was to combine the advantages of two strong-growth vehicles in a new, to-date vacant, vehicle concept.
They take its striking lines and transport these into the present. The tripartition on the front area, the striking middle line and the air intakes is formative. From the first rendering to the first model and to the concept car the best possible solution was sought between technicians and designers in order to present a vehicle feasible for production and economically viable. As development service provider and full service vehicle supplier Karmann does not pursue the goal of developing its own car but giving car makers impulses for their new trends with concept studies. Moreover, the chassis specialists from ZF and the engineers from Karmann are the proof of this by successfully carrying out a very complex projectin close cooperation.
Body solutions In order to satisfy crash safety requirements the body of the Sport Utility Cabrio had to be additionally reinforced. The existing floor of the basic vehicle offered the possibility to be reinforeced with a second floor plate. The newly designed sandwich structure provided the necessary rigidity for the four-door Convertible. However, the locking systems were integrated into the shortened B-column to deflect the resulting forces in case of a side crash.For comfortable access to all four seats an innovative door concept was created whereby driver and passengers can open the rear doors in the opposite direction independently from one another and completely collision-free.
In addition, the engineers developed evacuable seals, which are inflated by two separate leak-proof lines when the doors are closed. When opening the doors the air is expelled from the gaskets so that the doors swing open without any problems. An additional bolt centers the closed doors with one another, prevents the opening of the doors by the air stream and reduces the vibrations. The weight of the individual components also plays a decisive roll in the design of the doors. Instead of the conventional monocoque design the engineers use a spacious framework with hollow structures - the so-called space frame design. The resulting weight saving amounts to about 3.5 kilograms per door.
Comfort and Doors Front and rear doors opening in opposite direction as well as ease-tomaintain are the two aspects are the basis for the door design of the Sport Utility Cabrio (SUC). An additional benefit of this design is the added comfort in getting in and out of the SUC, and the passengers can open the rear doors to an opening angle of 90 degrees. A rotating hinge, an encased cable duct and door tread lighting are the optical features of the design. The so-called "dorstop" system provides additional comfort. It fixes the door in every position between zero and 90 degrees and prevents the doors swinging back even when the cars is parked on slope. The "Dorstop" system enables to lock the door at 60 degrees.
In order to be able to use this feature comfortably and easily sliding door handles have been developed. The interior door handles of the rear doors adapt according to the ergonomic needs of passengers getting in and out of the car. Regulated by Bowden cables, the handles move in a manner that makes them easy to reach from any position. Moreover, a sophisticated sensor system controls all functions. The external door handles, flush with the exterior surface, further add to the elegance of the SUC. They protract when touched and control the following functions: unlocking the door as well as additional locks in the side panels and sills and bleeding the sealing system and the short-stroke control for the windows. The tailgate is on the contrary equipped with a conventional handle, but likewise has the "Dorstop system".
Roof system and luggage space With the concept vehicle "Karmann Idea" roadster in 1991 Karmann already presented a roof design whereby a fixed roof part served at the same time as cover for the fold-away soft top. The high level of stability of the roof design at the same time improves the occupants' protection. This Sport Utility Cabriolet roof concept utilizes the Karmann ZFolding system and includes an integrated sunroof. It spans the SUV's occupant and luggage compartments, with an area of more than 4 square meters it is by far the largest fully-automatic powered top in the world which folds away in 13 seconds. It has a polycarbonate sunroof, which is integrated into the soft top, and gives the driver the feeling of being in a cockpit.
With the soft top up, this rear window concept allows for flow through ventilation and the pass through of bulky articles for easy transport. The rear door can act as a tailgate for the transport of long materials. Additionally, when the rear seats are folded into their stowed position the Sport Utility Cabriolet provides luggage space comparable to a classic station wagon.
Chief Stylist Jörg Steuernagel: "The time is ripe for a new niche - the Sport Utility Cabrio, abbreviated to SUC. In 1995 Mercedes SLK founded a new niche with the first modern retractable hardtop (RHT) from Karmann. Ten years later RHT models are rolled out by nearly all volume manufacturers or are just about to enter on the market. The first Sport Utility Cabrio, abbreviated to SUC, which Karmann together with ZF has put on its wheels for Frankfurt Motor Show 2005 opens the door to a new niche. Jörg Steuernagel, Chief Stylist at Karmann explains how the idea came about and what goals have been involved in it.
Vans, SUV's, Cabrios and RHT models - why does the car market still need a new niche? And why now?
Jörg Steuernagel: We intensively observe the market - the trends come from America, and from California in particular. It is worthy of note that women contribute to an essential part of the SUV boom, which is now also reaching Western Europe. Above all, mothers with children appreciate the space and the safety of the SUVs. Associated with the long-running trend in open vehicles the idea grew to develop a four-door SUV with a comfortable convertible roof as a concept and impulse giver for a to-date vacant market segment. The sales potential amounts to up to 180,000 units a year. The time is therefore ripe for the new niche - the Sport Utility Cabrio.
What prognosis are you basing yourself on? Jörg Steuernagel: In the study from Polk Marketing Systems a period from 2009 to 2015 was considered. Individual vehicles can achieve annual production of 20,000 to 30,000. The SUC has the by-far largest market because of the wide spread of the SUV in the USA. Also station wagons and van drivers are potential customers.
What makes you so sure that the prognosis will come true?
Jörg Steuernagel: The estimations are rather conservative. When we presented a similar study on the retractable hardtops (RHT) in 1999, we based ourselves on about 200,000 vehicles per annum. Actually today about 400,000 RHT models are being built.
When was the decision for the Concept Car made and what characterizes the design?
Jörg Steuernagel: The project started in spring 2004. The basis had already been laid by ZF and Karmann prior to this in separate projects and now it came together. The design includes as all concept cars from Karmann style elements of the VW Karmann Ghia Type 14 and 34 and redesigns them.
When will the first SUC hit the streets?
Jörg Steuernagel: That depends first and foremost on the car makers who want to include a SUC in their model range. In spite of the fact that the concept car is road ready, this new segment is a very complex subject. Therefore we do not imagine a series start before 2009.