Toyota FT-EV Concept, 2009
The DESIGN
The objective was a new kind of city car, one that would accommodate four people within an overall length of less than three metres. The result was a landmark solution that will have a long term influence on Toyota's future vehicle development. Toyota iQ is the ultimate expression of refined, yet environmentally efficient urban mobility.
The extraordinary interior space in a car that measures just 2,985mm long, 1,500mm high and 1,680mm wide is a tribute to the determination and ingenuity of Toyota's design and engineering team.
It can carry four people (three adults plus a child) in comfort and safety at motorway speeds, is just the beginning of the story. Starting with a clean sheet of paper, Toyota has created an ingenious and distinctive new city car. And with its proportionally large, 2,000mm wheelbase, Toyota iQ has a compact yet muscular stance that is like no other car.
Toyota iQ's design represents the essence of Toyota's J-factor heritage, which embraces the finest elements of Japanese aesthetics, such as miniaturisation and modernism. Most importantly it brings contradictory elements into harmony, such as "small yet spacious" or "hi-tech yet human".
SIX INNOVATIONS PRODUCE A BREAKTHROUGH IN VEHICLE PACKAGING
Toyota iQ's remarkable interior volume is down to its comparatively long 2,000mm wheelbase and short overhangs - 530mm at the front and 455mm at the rear. Interior length from the rear end of the instrument panel to the hip point of the rear seats is an impressive 1,238mm. To achieve this breakthrough, six space-saving engineering innovations were developed.
Integrating the front-mounted differential in a conventional transmission layout allowed Toyota iQ to be built with an ultra-short front overhang. This reduced overall length while at the same time increasing the length of the passenger compartment. Ingeniously this not only reduces the amount of space required for the engine compartment, it also allows the large diameter front wheels to be positioned at the far corners of the vehicle. This shortens the overhangs, which in turn improves stability and manoeuvrability.
Employing centre take-off steering gear and placing it higher in the engine bay means the transmission, engine and differential could be repositioned. The engine compartment could then be made considerably smaller, further reducing the front overhang.
The traditionally fuel tanks are located underneath a car's rear seats. By making the tank flat, reducing it to just 120mm in height and solving the problems of rapidly changing fuel surface levels that such a design would normally create, the tank could be relocated under the floor. Toyota iQ's fuel tank has a 32-litre capacity, giving an ample driving range. Angling the rear shock absorbers backwards allows interior rear space to be increased.
The slimness of the seatbacks frees up an extra 40mm of rear passenger room at knee height. The seats weigh up to 30 per cent less than conventional ones, contributing to overall fuel efficiency and low emissions. Using extruded pipe materials rather than high tensile sheet steel ensures the structure is rigid. The slimmer designs, with integrated headrests, save space without sacrificing comfort or safety.
Reducing the size of the heater and air conditioning unit by 20 per cent compared to the Toyota Yaris allowed the engineers to make significant space savings without compromising performance. This means the blower unit, usually found in front of the front passenger, could be integrated with the main ventilation unit in a central position. This innovation allowed the front passenger area to be moved forward, freeing up cabin space and increasing leg room.
The innovative asymmetric dashboard was designed to open up the whole cabin area. It ensures ample leg room for the front passenger, even when the seat is in its furthest forward position. The sliding seat configuration allows an adult 190cm tall to sit comfortably in the rear seat behind a front passenger of the same height. Shoulder-to-shoulder distance between driver and front passenger is 50mm wider than in Yaris and bears comparison with a C-segment vehicle. The all-round space and seating layout means there is ample room for three adults plus either a child passenger or luggage behind the driver.
ENGINEERED FOR ENVIRONMENTAL EXCELLENCE
The Toyota iQ represents the successful outcome of Toyota's well-established drive to reduce the environmental impact of its vehicles without compromising performance and driving dynamics. With CO2 emissions as low as 99g/km (with manual transmission), it is clearly a city car that's in the right place at the right time.
Its innovative, aerodynamic packaging has been achieved through a low overall height, low centre of gravity and wheels pushed out to the four corners of the car. This gives agility at low speed and unprecedented stability for a small car on motorways and winding roads. A minimum turning radius of 3.9 metres further enhances its nimble handling, even in tight city streets.
The 1.0-litre VVT-i petrol engine, winner of the 2008 Engine of the Year award in the sub-1.0-litre class, is a lightweight, three-cylinder unit, producing 67bhp (68 Din hp) at 6,000rpm and 91Nm of torque at 4,800rpm. Combined with a high-ratio five-speed manual transmission, it returns 65.7mpg in combined cycle driving and 99g/km of carbon dioxide (figures provisional prior to final homologation). This keeps Toyota iQ under the UK's 100g/km threshold for Vehicle Excise Duty, a benchmark that is also used for tax purposes in other major European markets, too. Specified with Multidrive transmission, the engine emits 110g/km of CO2 (provisional figure).
The Multidrive transmission
Multidrive uses Toyota's latest continuously variable transmission (CVT) technology to give a very smooth shift feel while optimising the balance between performance and fuel economy. It continuously monitors and selects the most appropriate gear ratio and shifting speed, automatically eliminating "shift shock" or jumps while changing gear. It maximises engine torque without unnecessary acceleration and smoothes gear ratio changes, for example limiting uphill shifts and making downhill shifts to achieve optimum engine brake force. The system provides all the city-friendly characteristics of a conventional automatic gearbox.
Models equipped with Multidrive feature an ECO driving indicator lamp on the multi-information display. This encourages more economical driving by signalling when fuel is being saved and, consequently, emissions are reduced. Current and average fuel consumption are also permanently on display.
The Gear shift indicator
Models with manual transmission are equipped with a gear shift indicator which shows the driver when to change up or down a gear to achieve the best environmental performance. The system takes driving conditions, accelerator pedal pressure and vehicle speed into account and can return fuel consumption savings of between 0.5 and three per cent compared to normal gear shifting, depending on individual driver habits.
The Future developments
The Toyota iQ's innovations will be adapted and evolved for future Toyota models. The car is a major milestone in Toyota's environmental commitment and efforts to develop technologies for much lower emissions.
