(Editor's Note: It's kinda' hard to respect greencar.com when they go and do something utterly stupid like naming a 20mpg SUV as their "Green Car Of The Year", but that's what they in fact did in 2007. You can take a look at the article yourself and be dumbstruck as you read some rather obtuse quotes like "People don’t think ‘green’ when SUVs are concerned, and for generally good reason since SUVs often get poor fuel economy compared to most other vehicles" immediately followed by this gem: "Chevrolet’s achievement is even more apparent during city driving where a large percentage of SUVs spend their time every day."
Brilliant! They open their article by citing the two major flaws of the SUV trend (they inherently inefficient and their sheer size is dangerous to others and needlessly congests our roads), but then go on to extol the virtues of one that manages to get 20 miles per gallon instead of the usual 15!
Hopefully those responsible have been sacked!
The reason I bring this up is because they do occasionally cover some excellent cars featuring exceptionally bright ideas... one of which I'm talking about at the end of this article.)
The founder of Lotus, Colin Chapman, believed that the two most important characteristics of a sports car were minimum weight, and maximum handling. Lotus' are truly uncompromising cars, as adept on a race track as many purpose built race vehicles. There is rarely any "excess" to be found in a Lotus. They are truly minimal sports cars, even in their fully "streetable" form. Alongside these, Lotus offers cars like the
2Eleven which truly push the boundaries in lightweight performance.
Chapman also pioneered the use of light weight composite materials in his Formula 1 cars, as well numerous other innovations in suspension and aerodynamics.
What does all that have to do with green cars?
There are three things that make sports cars fast: power, weight, and aerodynamics. Two of those three are equally important to fuel efficiency!
-Aerodynamics are a defining characteristic of highly fuel efficient cars. Hybrids like the new Honda Insight and Toyota Prius look that ugly for a reason: so they can slip through the air with the least amount of resistance and thereby get the maximum fuel economy. Read any article featuring tips on hypermiling and you will undoubtedly notice they always counsel removing roof racks, bike racks, etc. to reduce aerodynamic resistance.
-The other significant contributing factor to getting better mileage is weight reduction. More and more car makers are looking to composite materials as alternative to steel to make their cars lighter. Mazda, for example, managed to make their brand new Mazda6 lighter that it's predecessor despite the overal vehicle itself being slightly larger. The all new Mazda2 (available everywhere but North America for now) is over 200 pounds lighter than the outgoing model, without cutting the size of the vehicle. Again, any hypermiling article you're likely to read will point out that carrying 50 extra pounds in the trunk can noticeably affect your car's gas mileage.
That being said, Lotus doesn't stop there. They're actively developing their own versions of "green cars", and I'm not talking solely about "British Racing"...
-E85 Burning Exige
265EStarting with the ultra-lightweight (2050 lb.) Exige, Lotus proceeded to convert it to run on E85 biofuel (85% ethanol - 15% gasoline) whilst putting out 264hp, a boost of 46 horsepower over the stock Exige, making it the most powerful street legal Exige they'd ever made up to that point. The results: 0-60mph in 3.88 seconds, 0-100mph in 9.2, and a top speed of 158 miles per hour!
But how "green" is it? Running on E85 the 265E has a CO2 output of less than 100g/km. According to Toyota's own site the
much vaunted Prius, the poster-car for tree-huggers everywhere, has a CO2 output of 104g/km.
Lotus didn't stop there though. The E85 fueled Exige is just a case study... the first step in developing a true enthusiasts car that can run on a variety of fuels, both conventional and alternative.
Tri-Fuel Exige 270E
The natural progression of the E85 powered Exige was the tri-fuel powered Exige 270E which runs on any mixture of gasoline, bioethanol and methanol. Yet this time they got 6 more horsepower out of the engine for a max output of 270hp. By far the most interesting facet of this tri-fuel car is the fact that the methanol it can run on can be produced synthetically from CO2 in the atmosphere. This process would allow the 270E to achieve carbon neutrality. From the Lotus website:
Methanol (CH3OH) can be produced synthetically from CO2 and hydrogen. Ultimately, emerging processes to recover atmospheric CO2 will provide the required carbon that can entirely balance the CO2 emissions at the tailpipe that result from the internal combustion of synthetic methanol. The result is that a car running on synthetic methanol, such as the Exige 270E Tri-fuel would be environmentally neutral.
As well as being green, the great benefit of synthetic methanol is that it would use similar engines and fuel systems to those in current cars; and synthetic methanol can be stored, transported and retailed in much the same way as today's liquid fuels such as gasoline and diesel.
Synthetic methanol also possesses properties better suited to internal combustion than today's liquid fuels, giving improved performance and thermal efficiencies. And it is ideal for pressure-charging (turbocharging and supercharging) already being introduced by manufacturers to downsize engines in a bid to improve fuel consumption.
This alone is quite possibly the coolest development of all!
You can read more about both these case studies HERE at Lotus' official site.
Lastly, and possibly the most interesting "green" case study from Lotus is the Eco Elise.
Lotus went an entirely new direction with the Eco Elise. Instead of focusing simply on fuel and emissions they looked at how they could make the car green from bumper to bumper by using renewable, sustainable, and recyclable materials. Instead of using carbon fiber mat as a base for the composite body panels they used hemp fiber, grown locally. Not only is hemp strong enough to substitute the carbon fiber in this application, but it also obviously consumes CO2 (via photosynthesis) prior to being harvested, pushing the Eco Elise towards carbon neutrality. While the resin it's presently bonded to isn't recyclable yet, Lotus hopes that a natural resin can be developed in the future, thereby making the body panels fully recyclable.
The Eco Elise is also painted with a water-based paint co-developed by Lotus and DuPont, eliminating harsh chemical solvents, as well as needing lower curing temperatures allowing Lotus to expend less energy in the painting process.
Moving inside, hemp is again used as a carbon fiber substitute in fabricating the structure of the seats, which are then covered with a natural wool, which is a great idea if not for the fact that some (like myself) are allergic to pure wool. Instead of dying the wool to the color they want, Lotus designers simply selected specific breeds of sheep to get the desired shade. (Obviously, you cannot get a bright orange interior in this car...) For the carpet, they used another renewable crop... sisal.
On a purely technological side (and one of the features that interests me the most about this study) a pair of solar panels are integrated into the roof. These panels provide power to the cars electrical systems, relieving the engine of the extra load and helping to improve fuel economy. A significant aspect of this feature is that these panels are embedded in a double curvature roofline. This is a feature I would hope many manufacturers could one day implement into any sort of production car... not simply their "green" concepts.
The end result: not only is the Eco Elise greener from beginning (production) to end (disposal/recycling), but Lotus also managed to cut a total of 70 pounds off the standard car's weight. They even saved 3 pounds by simply re-evaluating the sound system and choosing lighter components.
For a little more info, as well as some pictures, you can read greencar.com's review of the Eco Elise HERE.
