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Read your article on being wary on fuel saving devices and thought you might like to have a look at this one and let me know what you think.

The address is www.tunit.com

Pete

From the "Ask Jack" archive - 14 December 2009

Thanks for the feedback on the AA's recent fuel saving devices article.

From what I know about that particular product it is more performance oriented.

They can re-chip a computer to enhanced power which basically takes an engine outside a manufactures built in cushion or comfort zones.

Manufacturers always build in these comfort zones rather than have engines on the limit at certain points and to ensure a smooth overall driving performance.

When an engine is re-chipped you will often find gains in some areas and losses in others depending on what you want to achieve.

I don't believe you could successfully re-chip a computer to improve fuel economy and retain good overall performance. The manufactures work very hard to get that balance spot-on in my opinion.