Lotus Engineering has unveiled the Lotus Exige 265E with a supercharged 1.8-litre engine – despite running on bio-ethanol
Lotus Engineering, the engineering consultancy division of Group Lotus, has developed a bio-ethanol E85 version of the Lotus Exige.
The research vehicle is a true Lotus (it weighs just 930 kg unladen) and is called the Lotus Exige 265E.
The figure 265 indicates the approximate horsepower and is consistent with the naming strategy of other one-off and limited-run Lotus variants such as the Lotus Sport Exige 240R; the letter E indicates the environmentally favourable bio-ethanol E85 fuel (85 per cent ethanol alcohol and 15 percent petrol/gasoline) that powers this extremely high-performance sportscar.
Key to this performance is a slightly modified version of the 1.8-litre 2ZZ VVTL-i high-revving four-cylinder engine from the standard Lotus Exige S with a Roots-type supercharger and intercooler. This now gives an estimated set of performance figures that would thrash the majority of ‘Super-Unleaded’ performance cars: 0-60 mph in 3.88 seconds, 0-100 mph in 9.2 seconds and a top speed of 158 mph. In fact the Lotus Exige 265E is probably the world’s quickest road-legal E85 bio-ethanol car.
Key changes have been made to the fuel system and the engine calibration, and the four fuel injectors mounted on the inlet manifold have been enlarged. Two additional fuel injectors have been fitted at the supercharger inlet to increase the amount of fuel being injected in to the engine under higher engine loads and to further cool the charge air prior to combustion.
Bio-ethanol can be made from bio-mass plant crops such as cereals, sugar beet, sugar cane and wood. As these plant crops grow, they absorb carbon dioxide from the atmosphere, which then partly offsets the carbon dioxide (CO2) emissions produced during the burning of the bio-ethanol fuel in the car’s engine.
Different bio-fuels were considered for this research project, including bio-methanol, bio-ethanol and bio-butanol. E85 bio-ethanol was finally chosen as the fuel as its characteristics allowed the engineering project team to enhance the engine’s performance. The fact that this vehicle uses a pressure-charged engine provided even more opportunity to exploit the performance characteristics of a high-octane fuel. Ethanol has a high octane rating, which allows an optimum timing for engine ignition and has a fast flame speed in the cylinder, so the fuel burns faster, increasing the efficiency of the engine.
The beauty of ethanol is its ability to produce more power in the engine than with conventional petrol/gasoline fuel. The Lotus Exige 265E now produces 264 hp (197 kW, 268 PS) at 8000 rpm, and 184 lbft (249 Nm) of torque (at 5500 rpm), up by 46 hp (34 kW, 47 PS) or 21 per cent and 25 lbft (34 Nm) or 16 per cent over the standard petrol/gasoline Exige S. With the total weight of approximately 930 kg (unladen), the power-to-weight ratio is approximately 283 hp per tonne (211 kW per tonne, 287 PS per tonne).
Ethanol has less stored energy per unit volume than gasoline so the fuel economy is poorer; however, as E85 ethanol is 85 per cent sourced from renewable bio matter, there is a net reduction in carbon dioxide (CO2).
Geraint Castleton-White, head of powertrain for Lotus Engineering, explains the rationale behind the Lotus Exige 265E technical demonstrator: “We wanted to prove the point that ‘green’ sportscars can also be very-high-performing sportscars. The fact that we have produced a research version of the Exige that is more powerful than the standard road car is a testament to the benefits of going green. We are also pleased that this vehicle demonstrates our engineering capabilities, our understanding of flex fuel vehicles and our knowledge of emerging fuel technologies. It also promotes bio-ethanol as a fuel of choice for the enthusiastic driver as well as the environmentally conscious driver.
Mike Kimberley, chief executive of Group Lotus, explains the Lotus ‘Green Strategy’: Lotus Engineering is actively pursuing technologies that will improve the efficiency and environmentally friendliness of engines in the future. Carbon dioxide reduction is a priorityas is anything that can reduce our reliance on fossil fuels. We are one of the world leaders in powertrain engineeringespecially in the internal combustion sectorand we are researching into all areas of alternative and conventional fuels to get greater efficienciespowerperformance and reduced net emissions; and Bio Ethanol research is one area where we are expert. The problems that are facing the automotive industry at the moment are challengingand these solutions fit with the Lotus culture and expertise.”
Mike Kimberley continues: “We have decided to develop a thorough understanding of the techniques and technologies of what alternative fuels can achieveto produce vehicles that are both fun to drive and environmentally friendly. We are also workinggloballyon hybrid and electric vehicles together with governments and universities andas an engineering organisationwe have a duty and a desire to promote these ideas to a worldwide customer base.”
The final sign-off test drive was completed just five weeks after the project was instigated and has resulted in a demonstration vehicle that not only excites the driver but also is at the forefront of environmentally friendly vehicles.
The next phase for the vehicle is to upgrade the calibration to a flex fuel spec to allow use with initially gasolinefollowed by the possibility of a multi-fuel-flex calibration to use fuels such as bio-methanol and bio-butanol in addition to the conventional gasoline/petrol and bio-ethanol.
The Lotus Exige 265E is purely a research vehicle for Lotus Engineering and Lotus does not intend to put the car into production or sell aftermarket kits for Lotus Cars.
For more informationvisit www.grouplotus.com
“
