Late in 2006, we started looking at the battery electric vehicles on the market at that time, and we started thinking that we may be able to build a low energy car that was capable of much more than just city use. 9 months of background research, calculations, debate (sometimes heated!), and sketching followed, and by the summer of 2007 we felt sure that the underlying concept of the E4-Coupe gave us a vehicle with great performance and usable range using batteries alone.

The car we are entering for the Progressive Automotive X PRIZE is a sleek 4-seater, four-wheel drive coupé-style battery electric vehicle (BEV), and it will be entered into the Mainstream Class. It is our own “clean sheet” design, based around the fundamental principle that it should use the minimum amount of energy possible in any given journey. This way, emissions are obviously reduced as a result of the reduction in energy consumption, but this reduced energy storage requirement also allows alternative choices for on-board energy storage to become viable.

In addition to designing the first vehicle for batteries alone, we have also chosen to “package protect” for a variety of range-extending energy storage and power generation systems (to be tested in future vehicles), including a hydrogen fuel cell and even a small internal combustion engine.

Most of the early work under-pinning the concept was therefore targeted at understanding how sensitive is the car’s energy consumption to changes in weight, size, aerodynamic drag, mechanical efficiency and many other parameters. Rather than pursuing any one of these characteristics to an extreme solution however, we have tried to take a pragmatic approach to finding a sensible balance so that the car we build will be fast and efficient but also attractive to look at whilst being reasonably cost-effective to manufacture.

The E4-Coupe that we will enter into the Progressive Automotive X PRIZE will be fitted with a sizeable battery pack, based around the most cost-effective lithium cells available at this time, and it will be fitted with four separate electric motors, one driving each wheel. The top speed of the car will be over 100mph, and the acceleration will be more impressive still due to the high torque and four wheel drive configuration. The location of the battery pack (under the floor of the car) also gives the E4-Coupe a centre of gravity height comparable with most single-seater race cars, despite its much higher ground clearance, and this will allow the car to corner and brake as well as it accelerates.

Delta Motorsport has been following the Progressive Automotive X PRIZE from the outset and we are very excited to be taking part in the competition with our Ultra Low Energy Vehicle. The E4-Coupe allows us to demonstrate our motorsport heritage and wide range of capabilities in producing a vehicle to challenge for the Prize. For example, efficient aerodynamics and light weight structures are commonplace in motorsport and these are key elements in the design of a vehicle capable of meeting the requirements of the Prize.

The challenge of the Progressive Automotive X-Prize is to build real cars that people want to buy, and we believe the objectives and regulations of the competition are absolutely sound. Interestingly, we feel that there’s much greater scope to innovate within the broad regulatory framework of the X-Prize than in any top level motorsport category, and surely that’s a challenge that no self-respecting engineer could resist!