The cobweb on the pump nozzle was a bit of a clue. Then there was the guy behind the till who confessed he’d never seen anyone use the bio-ethanol pump before; Lotus may be making a minor song and dance about developing an Exige to run on the new, green wonder fuel, but it’s clear that most of the rest of Britain is blissfully unaware of why bio-ethanol – or alcohol if we’re to cut through the marketing waffle – is worth getting excited about.
What’s so special about ethanol?
From a PHer’s viewpoint, what makes ethanol stand out in the world of fuels is that it burns very rapidly and has a very high octane rating – around 106-110 RON – so, with the help of a turbocharger or a supercharger, it can unlock more of your engine’s inherent power and performance potential.
In the case of the experimental Lotus Exige 265E that we’ve just test driven, power rises from the standard Exige S’s 218bhp to 264bhp, while the torque climbs 16 per cent to 184lb ft. All this is with very few changes to the 1.8-litre, four-cylinder, supercharged Toyota motor; there are a couple of extra fuel injectors on the inlet side of the supercharger, reprogrammed engine management, and that’s pretty much it. And jeez is it quick!
The other big claim for ethanol is that it produces about 70 per cent fewer CO2 emissions, provided your calculations take into account the fact that as the plants that are the raw materials for the fuel grow, they take carbon dioxide out of the atmosphere and turn it into oxygen. It also emits massively less nitrogen oxide, a ‘greenhouse’ gas with greater environmental impact than CO2 that for some reason hasn’t captured the attention of the press and green lobbyists.
And there’s another chilling reason why you might want to pay ethanol a bit more attention; current predictions are that we’ll have abundant oil only for about another 40 years and that once it starts to run short, aviation and the plastics industry will have priority over road transport. At that stage renewable energy sources will seem mighty attractive.
How fast is the ethanol-powered Exige, then?
It’s very fast. Lotus has calculated (on computers with brains the size of Manchester) that the 265E will sprint from zero to 60mph in 3.9sec and zap to 100mph from standstill in 9.2sec. Top speed is 158mph.
Impressive though they are, those figures don’t reveal all. Riding shotgun around the Hethel test track with one of Lotus’s top development drivers, Gavan Kershaw, he explained that the 265E exits the circuit’s famous Windsock corner about 10mph quicker than the Exige S. And approaching the chicane wall at the end of the main straight at 140mph+, Kershaw also pointed out that you’d struggle to beat that speed in a twin-turbo V8 Esprit. Apparently the 265E is significantly quicker all the way around the track, to the extent that the brakes in the car have been upgraded to four-pot callipers at the front working on larger diameter (310mm drilled and vented) discs.
Out on the road you feel the advantages of the bio-ethanol fuel in a number of ways. Firstly there’s the car’s speed, which is noticeably greater than that of the Exige S and easier to access than that of the limited edition 240R. The biggest difference is at the top end where the superior volatility of ethanol in comparison to petrol really makes itself felt with a solid, relentless stream of acceleration all the way to the 8500rpm limiter. What could be tricky to explain away in court with the 265E is that its natural speed down the road seems to be just the other side of 100mph, so keen dial watching is advisable, particular after you’ve overtaken slower traffic.
__________________
Essential facts
Performance
- 0-60 mph: 3.88 seconds
- 0-100 mph: in 9.2 seconds
- Top speed: 158 mph
Key engine changes
- Fuel system
- Engine calibration
- Four fuel injectors 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.
Other changes
The added performance has prompted Lotus to upgrade the brakes to four-piston AP Racing calipers with sport brake pads and increased diameter 310 mm drilled and vented discs at the front. Brembo single-piston sliding rear calipers with 282 mm diameter discs are fitted at the rear.
Benefits of bio-ethanol
The Lotus Exige 265E now produces 264 hp at 8,000rpm, and 184lb-ft of torque at 5500 rpm, up by 46 hp or 21 per cent and 25lb-ft or 16 per cent over the standard petrol / gasoline Exige S. With the total weight of about 930 kg (unladen), the power to weight is some 283 hp / tonne.
|
The way the booze-sipping Exige ramps up to speed is also impressive. Compared with the petrol-powered car the throttle response is more eager and the delivery of power crisper – not that there’s much wrong with how the regular Exige S dishes out its performance, but it’s as though the whole of its system has been flushed through with some sort of miracle detergent that has left a cleaner, more muscular car in its wake.
Sounds fantastic – any downsides?
From a practical perspective there are still a few issues to sort out with bio-ethanol fuel. For starters, the infrastructure. The cobwebby pump mentioned at the start of this article was at a Morrisons filling station in Diss, Norfolk, and for the moment all the bio-ethanol outlets are in that part of the country as part of a trial to check the fuel’s viability – the spider’s efforts maybe aren’t a good sign.
Even with nationwide bio-ethanol pumps, though, there’s another difficulty. Per litre, bio-ethanol fuel – which currently is a blend of 85 per cent ethanol, 15 per cent unleaded – won’t take you as far down the road as straight petrol. Therefore you need to fill up more often, although if this fuel takes off in a big way then car makers would doubtless fit larger fuel tanks.
It could be interesting to see what happens at MoT time, because although the ‘(oil) well to wheels’ CO2 figure being bandied around by the likes of Saab suggests a 70 per cent reduction in that emission, at the tailpipe it’s greater than a petrol-fuelled engine. That could be attended to with a more sophisticated catalytic converter, but in turn it could bite into the power gains.
Then there’s the price of fuel. When we filled up bio-ethanol was 91.9p per litre against 94.9p for regular unleaded, a reasonable differential but not sufficient to take into account the heavier fuel consumption using bio-ethanol. Government assistance with fuel taxation is therefore required here, but we all know how helpful the government is when it comes to the needs of motorists…
Bio-ethanol, a fuel for the future – yes or no?
Probably. The performance gains you can achieve from it, as proven in the Exige 265E, are mouth-watering, particularly as they come with the added bonus of an overall reduction in CO2 emissions – you have your cake and you’re eating it, delicious.
Then there’s the fact that motorsport is embracing ethanol, especially in the US where in 2007 the Honda-powered Indy cars will be running on straight ethanol. The big US car makers are also pushing their ethanol-powered road cars with lots of marketing dollars, so the UK will probably follow suit soon.
However, bio-ethanol does need the government to get behind it and reduce tax before the general public (who are unlikely to care about the extra performance) pays it much attention.
As for the Exige 265E, the men from Hethel insist that it’s simply a rapidly rolling advertisement for the talents of Lotus Engineering and that it’s not destined for production. On the other hand, the guys in motorsport can see that a bio-ethanol fuelled racer, that would be allowed a larger fuel tank under the regulations and could run for longer than petrol-powered rivals between fuel stops, has plenty of potential in endurance racing.
![](data:image/svg+xml,%3Csvg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 4 3"%3E%3C/svg%3E)
![](data:image/svg+xml,%3Csvg xmlns="https://www.w3.org/2000/svg" viewBox="0 0 1 1"%3E%3C/svg%3E)