This book is for the typical motorist who, as shown in the first chapter, only looks at his engine when he remembers to check the oil level or has noticed a tendency to misfire under load. He could be aware that the car no longer gives the good mpg it gave when he bought it as an 'immaculate used car' and could be wondering what to do about it. This book will tell him. The richer motorists in their new Jaguars and Mercedes - the ones that flash past us on the Motorway - never worry about fuel consumption. This book is not for them. Here, then, is an explanation of the principles of tuning, fol lowed by a simple step-by-step DIY tuning schedule. A hard look is taken at the many magical economy devices offered in the Press. Two of these are shown to stand up to critical examination and honest testing, namely some electronic ignition kits and the Kenlowe electric fan. Two more devices show marginal gains in economy. Finally, we offer advice on how to approach the economy driving techniques of the successful Economy Rally drivers. Since we live in such a cynical age we find it necessary to state that we have no connections with, nor have received any financial inducements from, any of the recommended firms making tun ing equipment or economy aids. We must thank these companies for all the useful information they have supplied. A full list is given in the Appendix.