One of the world's car giants is proving you can make something big out of a small package.
DaimlerChrysler has unveiled four new versions of its tiny Smart car, which takes us a step closer to a having truly environmentally friendly city car.
But the latest Smart solutions still have their limitations. At best they prove that alternative technology, such as a plug-and-go electric car, still has a little way to become practical.
Field trials are now being done on Smarts powered by either a rechargeable battery, a small diesel motor or a combination of both.
There's nothing new in the technology itself, but Smart is adding its weight to finding a way to overcome the shortcomings facing both hybrid and battery technologies to make them work.
Of the four, the diesel has the biggest potential to make it to our shores. At present, Smart only makes the car in left-hand drive but Britain is applying pressure to get a right-hand drive, meaning it could then be available here.
The electric version of the Smart uses a sodium nickel chloride battery to drive a 30kW magnetic motor, giving the car a 115km range and a top speed of about 110km/h. The battery, which has a 10-year lifespan, can be charged overnight from any 240-volt power socket.
The big plus is that the battery car doesn't produce any harmful emissions. The downside is that the battery needs eight hours to be fully charged. And, like many batteries, it needs to be drawn down to be almost flat before being recharged.
The hybrid version of the Smart combines a 20kW electric motor with small 33kW 799cc diesel engine. Both motors can work together (to produce 53kW) or separately. The battery is recharged by the diesel engine and through regenerative braking. The car has a top speed of 135km/h and a diesel fuel consumption of an amazing 2.9l/100km.
In October, Smart will launch another hybrid version, called the Micro, this one based on the existing Smart Fortwo, which will switch off its engine when stopped to save more fuel.
It will be powered by a larger 999cc three-cylinder petrol engine, combined with a special belt-driven high-torque starter generator, which supplies the vehicle's electrical system as well as replacing the conventional starter motor.
The generator fires up the petrol engine as soon as the driver takes their foot off the brake pedal. The car will have a top speed of 145km/h and a fuel consumption of 4.3l/100km.
The fourth new model, the CDi, uses the world's smallest direct-injection low-emission turbo diesel engine and is claimed to be the world's most economical vehicle using a conventional combustion engine.
The 33kW three-cylinder engine delivers a fuel consumption of just 3.3l/100km, with a range of 1000km between refills. This clever engine recycles up to 60 per cent of cooled exhaust gases in the combustion chamber and uses two injections of diesel into the cylinder head.
The first small injection is ignited and preheats the cylinders before the main injection of fuel is delivered a few milliseconds later. Smart says this reduces engine noise, a big problem with diesel motors.