Toyota will reveal their new D-4d 180 Clean Power concept car and Prius GT at next month’s Paris Motor Show.

The Toyota D-4D 180 Clean Power concept car showcases Toyota’s advances in diesel engine technology, achieving substantial improvements in both performance and exhaust emissions. The engine will be developed from the concept stage into a production unit which will be launched in 2005, within the 1.9 to 2.2-litre category.

The D-4D 180 power plant is set to create a new benchmark in its class in terms of power and torque. Fitted to the Clean Power concept car, it delivers the world’s lowest combined level of nitrogen oxides (NOx) and particulate matter (PM) emissions for a diesel engine, respectively 50 and 80 per cent below Euro IV standards.

Its qualities are achieved through the use of the Toyota D-CAT system (Diesel Clean Advanced Technology), which has already been used in the 2.0-litre D-CAT engine for the Toyota Avensis. Central to the D-CAT’s performance are the DPNR (Diesel Particulate NOx Reduction) four-way catalyst and advanced second generation common rail injection system. These combine with other control systems and components to provide the most effective solution yet to reduce diesel engine emissions.

The new D-4D engine produces in the region of 183bhp and 400Nm of torque, performance that is significantly higher than that offered by other units in its category and matched only by higher displacement V6 diesel engines.

The Toyota Prius GT made its UK debut among some of history’s finest racing and sports cars at this year’s Goodwood Festival of Speed. Now the prototype model is to take its place centre-stand at the Paris Motor Show, demonstrating how hybrid power technology does not prohibit sparkling performance and driving pleasure.

The Prius GT is based on the production Prius model, developed to demonstrate the versatility of hybrid technology. It retains the combination of 1.5-litre petrol engine and electric motor in the Hybrid Synergy Drive system, tuned to deliver 147bhp. Modifications are simple: the GT uses the same engine, electric motor, generator and battery as the standard Prius.

The power output is higher than for any other 1.5-litre diesel or petrol engine on the market, while specific power output rises to almost 100bhp per litre. In regular production specification, the Toyota Prius delivers 110bhp.

To match the increase in power output, the car’s complete suspension system – shock absorbers, springs and anti-roll bars – has been upgraded for sharper handling and improved grip. The Prius GT also adopts the same tyres as the Toyota Celica sports coupe for greater grip and the hybrid battery has been moved further back in the vehicle to achieve a near perfect front-to-rear weight balance.

The GT has a stripped-out interior with a safety cage, harnesses and just two sports seats up front. As a result the weight of the car is 1,120kg, 180kg less than the standard production model.

More power and less weight mean significant gains in performance: nought to 62mph acceleration can be achieved in 8.7 seconds. In spite of the higher output, fuel economy and emissions levels are virtually unchanged when the GT is driven at normal speeds, due to the extra engine power being counterbalanced by the efficiency gains in the electric circuit and reduction in weight.