The Student Room Group
Reply 1
Maybe you should think about what makes a fuel efficient before starting on the details of the experiment.
Reply 2
As it shall not overlap with other subjects, I will only look at the price and how exothermic the reaction is and then simply compare what you pay/ what you get
Reply 3
Does fuel efficiency have to do anything with the fuel's price?? You may want to try googling or wikipeding.

http://en.wikipedia.org/wiki/Fuel_efficiency

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