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Cover an EXACT number of kilometers (100, 200, 300, 400…Km.) as you like, and try to keep a VERY REGULAR drive!



Keeping a "very regular drive" alone will make at least as much difference as they claim.

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WE DON'T ACCEPT



any complaint about the doubtful working, if you can not prove it concretely with the exhausting test !



"If you don't have a very elaborate test lab to prove it doesn't work, we will punch your TS card and tell you goodby".

For a lot less than 34 quid you can get a vacuum guage. Unless you are a very conservative driver to begin with, using these 3 tricks;
Get into as high a gear as practical as quickly as you can.
Hold a steady throttle.
keep the manifold at as low a pressure (high vacuum) as practical.

You will likely save more fuel than they claim.

They say it has a bloody strong magnet in it. Unless you are burning iron or a particular mixture of aluminium, nickle and copper, your fuel just doesn't care.
At least in the US, the gvt has set a CAFE (Corporate Average Fuel Economy) standard. Car makers who don't meet this are fined a lot of money. If this worked, they would most certainly be using it because Yanks are a horsepower mad lot.

Let's hope there's intelligent life somewhere in space 'cause it's buggar all down here. -- Monte Python