Ethanol: Don’t put that tiger in your tank
Wednesday September 28th 2005, 8:58 pm

It's not as green as you think! (image: Andy Singer)Ethanol is a type of alcohol distilled from fermented biomass materials like sugar cane or maize. It’s the same stuff you find in beer, wine and distilled spirits. It makes a reasonably good motor fuel as long as there are no rubber or plastic parts in the vehicle’s fuel system. Burns much cleaner than petrol and is technically a renewable fuel.

However, ethanol will dissolve or degrade rubber and plastic parts in a fuel delivery system which was designed for petrol. This can be extraordinarily dangerous as under bonnet or under car fuel leaks can cause fires that will engulf a vehicle in seconds.

John HoWARd has a mate in the the ethanol industry who would like to mix as much ethanol as possible into fuel labelled ‘petrol’ and doesn’t want to tell you about it. Perhaps he’ll tell your next of kin!

There’s a few other caveats about ethanol that HoWARd and Manildra probably don’t want you to know. Ethanol only produces about 50-65% of the thermal output per litre as petrol. Even if your vehicle’s fuel system is designed to handle ethanol safely, you have to burn about double the number of litres of it to go the same number of kilometres as you would use if burning petrol!

If HoWARd gets his way and mandates 20% ethanol content in your petrol, you’ll only be getting 90% of the thermal output you would get from a normal litre of petrol, meaning your car will have to burn 10% MORE fuel to go the same distance you would go on a litre of normal petrol.

Ethanol production also requires the use of fossil fuels like LPG in the distillation process as well as diesel for the farming operations. In fact, it requires more energy (1.34:1) to produce a litre of ethanol than you will get back when you burn it, meaning that it has a negative net energy balance.

Australia has some of the world’s largest reserves of natural gas, which is used to make LPG. Many cars in Australia are converted to burn LPG, notably taxicabs. Due to a taxation relief scheme, LPG costs around 45 cents per litre, when petrol is about $1.30 per litre. LPG produces about 85% of the thermal output of petrol and burns even cleaner than ethanol. It’s easily possible for a car to be equipped to burn either petrol or LPG.

Australia is a net exporter of LPG. Around 66% of Australia’s LPG production is currently exported, while unleaded petrol used in Australia is produced overseas and imported.

If John HoWARd was serious about reducing Australia’s dependence on imported motor fuels and not lining his mates’ pockets, drink it, don't drive it!he’d mandate that all new cars sold in Australia be capable of burning domestically produced LPG, instead of using that LPG to produce ethanol.

Better yet, HoWARd should subsidise UNSW‘s already advanced fuel cell technology which will power hybrid electric cars in the near future.

Ethanol is much better in a frosty beer than in your petrol tank. Write HoWARd and tell him to use some good sense in Australia’s energy strategy by promoting the use of LPG as a motor fuel and increasing government funding into fuel cell research and development.


3 Comments so far
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Why does my 1985 Peugeot GTI fuel injected 505 run better on Ethanol? I believe the octane rating is higher and it doesn’t ping like it does on unleaded even with octane boost added.
Why was ethanol used as a race fuel if it’s so lacking in goomers. I thought it was sposed to have extra get up and go. I agree it’s corrosive. It melts paint so it needs to be handled carefully. No I’m not about to start drinking thinners.

Comment by Dan Kellaway 10.16.06 @ 10:11 pm

Dan, if your Peugeot pings on unleaded, check the ignition timing. If the timing is OK, buy better quality fuel. No reason why a modern engine with a compression ratio in the 8:1 neighbourhood should be pinging on 87 octane unleaded unless there’s a timing problem.

A lot of people think that Indy racers used methanol for greater power output; not true. The switch was made for safety reasons.

Methanol yields about 67% of the thermal output of petrol, compared to ethanol which produces around 50-65%. For many years, methanol was the fuel of choice for racers, though many racing series which once used methanol (i.e. Indy 500) are switching to ethanol (as of 2006) as it has become more available.

Racers use methanol mainly because it is miscible in water and thus methanol fires can be extinguished with plain water, where petrol fires must be extinguished with foam or dry chemical. Methanol also is less flammable than petrol, meaning vapours are more difficult to ignite.

It was a 1964 crash at the Indianapolis Motor Speedway where drivers Eddie Sachs and Dave McDonald were killed, when petrol was still being used in Indy cars, which prompted the change to 100% methanol.

While ethanol and methanol produce less thermal output than petrol, you can get the same power output from an engine by simply pumping ~30% more of an alcohol fuel into the cylinders.

Comment by weez 10.17.06 @ 8:51 am

Yep adjust your ignition timing.Google your car info and the fuel you’re using and you should find what you’re looking for.

Comment by skite 03.15.11 @ 7:44 pm

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