Chassis & Body

Drive Train

On-board energy generation

Preliminary Specs

3D renders & Movies

HOST at the International Lisbon Auto Show 2006

HOST at the Exhibition of Knowldge and Innovation


The Human Oriented Sustainable Transport


Layout of the Powertrain

HOST is powered by a hybrid-electric propulsion system with a series configuration, which combines an electric motor with a battery pack and a conventional combustion engine to extend the range of the vehicle. The engine is never connected to the wheels, its sole function being to recharge the battery. In such a vehicle the drive train is completely different from that of a conventional car, as no drive shafts and no gearbox are required. The power is directed in the following manner:

The vehicle is moved by in-wheel motors. These electrical motors vary their speed and torque according to the requirements of the road (uphill, downhill, etc…) and power to them is supplied from two batteries. These batteries act like reservoirs, accumulating energy whenever movement does not use it and supplying it whenever movement is needed. Supercapacitors (not represented) supply the required peak current bursts.


Being mission oriented, the combustion engine can be optimized to operate at steady state to produce the exact energy required for the vehicle to accomplish the missions for which it is designed. In this way the engine always operate at peak efficiency conditions, being put to work whenever the batteries State-of-Charge reaches a minimum threshold and shutting off whenever a maximum threshold is reached.

In-Wheel Setup

Four in-wheel motors supply forward movement and recover energy from braking at low to moderate braking rates. Mechanical braking is still employed and so the wheel assembly is also provided with a braking pads and callipers.


On-Board Energy Storage Setup

Two batteries, capable of storing up to 2.8kWh of energy are used in HOST. The car-sharing platform requires less power and only one 1.4kWh battery is needed. The batteries have a very good power and energy density and even in the double configuration they weight less than 100kg and are smaller than the engine itself. Their material is Ni-Mh (Nickel - Metal hydrate).

In spite of the state-of-the-art technology of the batteries, these are not able to respond quickly enough to solicitations requiring large amounts of power such as in overtaking manoeuvres, or recovering from the huge amounts of power generated when braking in the heavier commercial configuration. A Supercapacitor is then used to deliver the peak current bursts.


The in-wheel motors layout provides HOST with two enormous advantages over conventional vehicles: it is a true 4WD vehicle, since any wheel can turn at any speed, regardless of the other wheels; and it is also 4WS – 4 wheel steering, due to the bespoke suspension and steering system installed.

The resulting easy traction and possibility of horizontal rotation give the vehicle new features to accomplish with missions requiring difficult access to narrow streets in central urban areas, particularly in the larger configuration.