Lotus Engineering Develops E85 Exige Research Sportscar

24 August 2006

Lotus Engineering, the engineering consultancy division of Group Lotus Plc, has developed an E85 version of the Lotus Exige—the Lotus Exige 265E—as a research car.

Powered by a modified version of the 1.8-liter engine in the standard Lotus Exige S, the Exige 265E is more powerful than its gasoline counterpart, producing 264 hp (197 kW) at 8,000 rpm, and 184 lb-ft (249 Nm) of torque (at 5,500 rpm)—increases of 21% and 16% respectively over the gasoline model.

The 265E can accelerate from 0-60 mph in 3.88 seconds, 0-100 mph in 9.2 seconds, and has a top speed of 158 mph.

Lotus considered a variety of biofuels for this project including bio-methanol, bio-ethanol and biobutanol. The group finally selected ethanol as the fuel as its characteristics allowed the engineering project team to enhance the engine performance. The pressure-charged engine provides even more opportunity to exploit the performance characteristics of a high-octane fuel. Ethanol has a high octane rating, allowing 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.

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.

—Geraint Castleton-White, Head of Powertrain for Lotus Engineering

Lotus Engineering is actively pursuing technologies that will improve the efficiency and environmentally friendliness of engines in the future. Carbon dioxide reduction is a priority, as is anything that can reduce our reliance on fossil fuels. We are one of the world leaders in powertrain engineering especially in the internal combustion sector and we are researching into all areas of alternative and conventional fuels to get greater efficiencies, power, performance and reduce net emissions and Bio Ethanol research is one area where we are expert.

We have decided to develop a thorough understanding of the techniques and technologies of what alternative fuels can achieve, to produce vehicles that are both fun to drive and environmentally friendly. We are also working, globally, on hybrid and electric vehicles together with governments and universities and as an engineering organization we have a duty and a desire to promote these ideas to a worldwide customer base.

—Mike Kimberley, Chief Executive of Group Lotus

The next phase for the vehicle is to upgrade the calibration to a flex-fuel spec to allow use with initially gasoline, followed 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 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.

The engine. The additional power The Exige 265E features a Roots-type supercharger (with a sealed-for-life internal mechanism) and air-to-air intercooler attached to the 4-cylinder, 1.8 liter 2ZZ-GE VVTL-i engine.

A roof scoop ensures that the air-to-air intercooler works as efficiently and effectively as possible in all climates and environments. All charge-air ducting has been kept as short as possible with large diameter pipes making sure that the bends in these ducts are not too tight, to the benefit of throttle response and efficiency. The Roots-type Eaton M62 supercharger is run from the crankshaft, and has an integral bypass valve for part-load operation.

The 2ZZ VVTL-i engine has two cam profiles—a high-speed cam and a low-speed cam. The seamless switch point between these two cams is completely variable depending upon driving conditions and engine load, and the driver will not know which cam is being used at any point. This gives the Lotus Exige 265E a smooth and linear surge of power from idle speeds all the way to the maximum 8500 rpm.

Four enlarged fuel injectors increase fuel flow into the engine under normal operating conditions. Two additional fuel injectors fitted at the supercharger inlet increase the amount of fuel being injected into the engine under higher engine speeds and loads. This has also enabled the engineering project team to take advantage of ethanol’s higher cooling effect to further cool the charge air prior to combustion, which in turn reduces the amount of power required to operate the supercharger.

The 265e uses a version of the Lotus T4e Engine Management system programmed to optimize the use of ethanol in the supercharged and intercooled engine.

Cool. But no mention of the fuel comsumption penalty. Is it 30% (like most flex-fuel vehicles in the USA) or is it more like the Saab BioPower's 18% hit?

The power and torque percentage increases are almost identical to the BioPower. This is encouraging as it shows that cars engineered for E85 can have engines downsized by 15-20% with no loss of performance.

JN2 made an important point, an E85 engines can be downsized for the same output. I wonder why they used a roots blower, centrifugal superchargers are more efficent.........

Because they produce a move favorable boost curve than a centri. The area under the curve is much larger for the roots. And Im sure its much cheaper to produce as well.

"We wanted to prove the point that green sportscars can also be very high performing sportscars." Umm, OK but the figures on CO2, NOX emissions seem to be missing from your (marketing) dept. press release, vroom, vroom.

I don't see why ethanol is being developed so much right now. E85 can't be pumped in the same pipelines as oil, and has only 85,000 BTU's per gallon compared to 115,000 with gas. What we really need is biobutanol- it has one more carbon than ethanol, it isn't corrosive, it can be pumped through regular pipelines, needs many fewer engine mods, and has a BTU rating of 110,000 per gallon. Also, it can be made in existing ethanol distilleries. see:

http://www2.dupont.com/Biofuels/en_US/facts/BiobutanolFactSheet.html

Ethanol is far cheaper in current production models ($1.80 vs$3.50/gal) and until we have a major shift in the ease of production of butanol, ethanol will continue to be more cost effective, even with the lower BTU content. As for the questions about CO2 values, the current gasoline Exige is gasoline rated at 22/29 mpg by the EPA. With a supercharger that would likely drop to 21/28 or so because of the higher losses. Because E85 is only 15% gasoline, it's very close to carbon neutral as a fuel.

Lotus makes those electric cars for Tesla. Perhaps a possiblility for the two would be for Tesla to make electric versions of Lotus sports cars. They may be plugin hybrids too.

Ethanol is far cheaper in current production models ($1.80 vs$3.50/gal)

cf.

http://www.cleanairchoice.org/outdoor/PriceForum.asp

Joseph, you posted a link to E85 pump prices. That has nothing to do with what I said, which is ethanol PRODUCTION costs. Thanks for trying though.

Sid,
I believe Joseph's link illustrates your miquoting on ethanol vs. unleaded gas pricing 1.80 vs. 3.50 when it is closer to 2.30 vs. 2.80 = $.50 Cost effective? (NO) The subsidy for ethanol, among the mostly heavily subsidized of energy sources, is 54 cents per gallon. In addition, the tax exemption for ethanol is 30 percent higher than that for gasoline. Gasoline marketers pay 18.3 cents per gallon of conventional fuel to the government while marketers of the ethanol blend only pay a tax of 12.9 cents per gallon. Carbon neutral? (NO) Corn ethanol derives much of its energy from fossil fuel inputs. As a result, the overall reduction in heat-trapping emissions achieved by using corn ethanol is only 10 to 20 percent per unit of energy delivered. Joseph, you posted a link to E85 pump prices. That has nothing to do with what I said, which is ethanol PRODUCTION costs. Thanks for trying though. I see. So the "production cost" of gasoline is$3.50 and they sell it for $2.92? I don't see anywhere where you said anything about "production costs" (as if that's relevant). What I did see you say is "Ethanol is far cheaper in current production models ($1.80 vs \$3.50/gal) and until we have a major shift in the ease of production of butanol, ethanol will continue to be more cost effective, even with the lower BTU content." So, what you're doing there is saying ethanol is "more cost effective" than gasoline, even though it has fewer BTUs per gallon.

So, take the price differentials you see on that site and plug that into mileage figures for any E85 vehicle. I ran a couple (using prices in Minnesota) and gasoline ended up being slightly cheaper. Ethanol certainly wasn't "more cost effective". Use pricing from places like Maryland, where ethanol is more expensive than gasoline, and then it's not even in the same ballpark.

Of course, all of this ignores the massive subsidies ethanol gets.

But thanks for trying, though.

If they were serious about exploring the potential of a "green" sports car, I suspect biodiesel or electric power would be the way to go. VW have already shown their diesel-powered Ecoracer concept car, and Lotus themselves are assembling the electric Roadster for Tesla Motors. Both of those seem like more promising approaches to me. However, there is a method to this E85 Exige madness. . .

I suspect this is mainly a promotional stunt for Lotus's engineering business. This is Lotus's way of speaking to Ford, GM, Toyota, DaimlerCrysler and saying, "Hey guys, we know how to work with ethanol too. Don't forget us next time you need help with a flex-fuel project!" As long as ethanol is being heavily subsidized in the USA (for political reasons), Lotus Engineering can make a grab for their share of the cake.

my daddy designed that engine, their only making one atm so u dont have to worry about ur stupid fuel prices, it was an idea and i bet u couldnt design an engine so there.

You will never see the theortical "30% drop" in fuel economy because that figure only takes into consideration the energy content of the fuels in consideration. In real life, due to the cooling effect of ethanol and it's superior octane rating, more tweaks can be make to the engine to regain horse power at less throttle opening. In fact, at 20-40% blends of ethanol, there is at least one scientific study (and many personal stories) showing INCREASES in fuel mileage when compared to gasoline only. And this is on both flex fuel and non-flex fuel cars. http://www.ethanol.org/pdf/contentmg...inal_12507.pdf

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