Fuel additives (and gadgets) lack firepower - Dr Karl

Last time, I began this series on fraudulent fuel economy devices, and discussed how an internal combustion engine actually turns petrol into forward motion.
Most of us have heard of the Australian-based company called Firepower. It built its considerable fortunes on selling a pill that would improve your fuel economy when you added it to your petrol tank — 42 per cent they claimed!
Firepower seems to be the latest in a long line of companies that appear with a miraculous product, siphon away buckets of money, and vanish, leaving a lot of people with empty pockets.
Firepower first burst into the media in November 2006, with the announcement of a $3 million sponsorship of the Rabbitohs, a rugby league football club.
Indeed, the actor Russell Crowe (a part-owner of the Rabbitohs) announced this sponsorship on Jay Leno's Tonight Show in the USA.
Firepower also sponsored the Sydney Kings basketball team, which kindly renamed itself the Firepower Sydney Kings.
Since then, Firepower has been linked to: federal and state politicians and bureaucrats; the Australian government agency Austrade; the former Australian prime minister John Howard; the former Australian ambassador in Pakistan; the arms trade in Romania; former German heads of Haliburton; the Western Force rugby club; the Tongan national rugby team; and even the Australian Superbike Championship; the Australian V8 Supercar racing team; and the Porsche Carrera Cup.
At one stage, Firepower was supposedly worth $3.5 billion. Pretty amazing for an empire built on a little brown pill (costing $1.50) that you pop into your fuel tank and which supposedly increases your fuel economy.
But there were problems. They refused to get their special pill independently tested, they didn't provide financial records to investors and they delayed their stockmarket listing.
Oh yes, there was another problem. The pill didn't actually improve fuel economy. What a surprise!
Getting back to the USA, the US Federal Trade Commission engineers have tested virtually every one of these fuel additives released over the last few decades. Not one has made any difference.
And think about the fuel line heaters and coolers. One bunch of salespeople reckons you can improve your fuel economy by heating up the fuel, while another bunch says the exact opposite and reckons you need to cool your fuel.
They can't both be right.
Let's move along from the fuel tank, and take a look at the mist of fuel droplets on their way into the car engine.
The ideal fuel-air ratio is about 1:15. If you have too much air, the engine runs too hot, and the emissions increase.
If you have too much fuel, you can lose economy, the emissions increase, and raw unburnt fuel accumulates on the inside of the cylinder walls.
This fuel can wash away the lubricating oil that sits between the cylinder wall and the piston, and so increase wear.
One 'gas-saving' device, the air-bleed device, allows small quantities of extra air into the fuel-air mixture. This supposedly allows less fuel in, so giving better fuel economy.
All it really does is overheat the engine and worsen the emissions out of the exhaust pipe. Vapour-bleed devices do the same thing, but they first run the air through a liquid, such as water, or water and anti-freeze, or something exotic.
Once again, neither of these bleed devices has ever been proved to work.
Another odd device in this category of 'gas-savers' is the mixture enhancer, whatever 'enhancing' the mixture means.
They claim to improve fuel economy by increasing the turbulence of the fuel-air mist. In reality, you want to reduce the turbulence.
They are placed inside the intake pipes before the fuel-air mist reaches the combustion chamber.
These mixture enhancers can be truly bizarre, with fans, tiny propellers, metal tubes with fins, and even a metal plate with holes in it.
You guessed it, they don't work either.
Another method is liquid injection. It has a little tank of water or methylated spirits that is hooked into the intake system of the engine.
These do give a very small improvement in fuel economy, but at a cost of increasing the engine emissions. And of course, they cost money.
The third category of fuel economy devices is quite technical. They have a mechanism to reduce the fuel burn by shutting down a few of the cylinders, when you don't need full power.
The big car companies have been trying to perfect this for a few decades.
In the early days, they had problems with engines self-destructing. But it's only recently that they have managed to shut down a few cylinders, improving the fuel economy without destroying the engine.
Can you believe that a backyard mechanic, without the massive resources that the car companies have, could make such a mechanism?
Some of these backyard devices did indeed give a tiny increase in fuel economy, but with an increase in emissions out of the exhaust pipe, and significantly less reliability in the engine.
Next time, I'll finish my visit to fuel-economy land with a few more devices, one of which works, but which you can use without actually buying.

See the article athttp://www.abc.net.au/science/articles/2010/02/16/2821231.htm?site=science/greatmomentsinscience