Driving for Economy

Abstract

Obviously, we must take advantage of any price wars that develop from time to time between the big petrol companies and occasionally between neighbourhood filling stations. We are particularly fortunate if our cheapest filling station is about a mile from our home on our way to work in the morning, since we can achieve two economies at the same time. The first economy is derived from the ‘heat-soak’ effect on the induction manifold. During the colder six or seven months of a typical British year one will often travel one and a half to two miles before the manual choke can be pushed completely OFF. However, as the car is standing at a filling station near home with the engine switched off, heat will be soaking from the hot exhaust manifold into the induction manifold. Quite often after this heat-soak the car can be driven off without the use of the manual choke. An automatic choke often reacts in the same way, thus making a small economy.