MORE CAR MILES

Gisborne Herald, Volume LXVI, Issue 20047, 20 September 1939, Page 11

MORE CAR MILES

PETROL ECONOMY GOOD DRIVING IMPORTANT POINTS TO BE AVOIDED Petrol economy, with the outbreak of war, has become a subject of immediate interest to nearly all New Zealand motorists so that they may obtain the maximum use and enjoyment from the limited quantity, of spirit that they are being allowed to use each month. Though the trade for many years has desired drivers tc ’acquire economical habits and methods, and has employed technical men to assist them, a great many motorists still regard the petrol consumption of a car as something inherent in its design and beyond their control. On the contrary, a great extension of the distance a car wiF run on a gallon of spirit can be obtained by taking care in car maintenance and in driving.

The seemingly extraordinary mileages obtained in tests that are usee to advertise certain models are not achieved by tricks, but by the adoption of methods available to every owner-driver. The average driver would not care to take the trouble that the skilled driver concentrating on petrol saving takes during such a test, but he can learn from the methods used on those occasions much that will give him more miles to the gallon. An 8 h.p. car should run 40 to 45 miles to the gallon, a 10 h.p. car 35 to 40, a 12-14 h.p. car 30, a 30 h.p. car (in this class are the popular mediumsize cars) 20, and cars over 30 h.p. (the very luxurious cars) 18.

The consumption can be calculated most easily if the filling station is visited only when the level of the petrol in the tank is at a predetermined mark and a note is made of the quantity purchased and the speedometer reading at each visit. The longer the time over which records are kept the more accurate is the calculation. Ifabits e? Driving-

Economy of pc'" I is largely a matter of economising in the power demanded of the engine of a car. Tc get the most power out of the petrol the engine must be in good condition, the placing of it in proper condition being work for a reputable firm. After that the two important factors are the condition of the car’s running gear and the methods by which the car is handled, both of which are directly within the control of most drivers.

Habits of driving have a much stronger influence on petrol consumption than most drivers realise. If those who accelerate powerful cars up an incline in a spectacular manner were to sec the petrol pouring into the carburettor, then most would hesitate to drive in such a manner again. All rapid acceleration is extravagant, ancl any quick application of the accelerator at all must be avoided: it should hr depressed only slowly.

Excessive use of the choke also wastes petrol. If possible its use should be avoided entirely. “Driving on the brakes’’ is another way of wasting power, for if the momentum that a car has can carry it to a place it is better to let the momentum do so than to use the engine and then waste in- friction on the brake-drums much of the energy obtained at the cost of petrol.

Judicious use of the gears also will assist drivers to drive their cars further than otherwise on the quantity of petrol allowed them. It does not pay to allow a car to labour on a hill in top gear, and if a lower gear is engaged the car should be driven at a moderate speed, because an engine revolving at an excessive speed consumes an undue amount of petrol. Since an engine uses an appreciable amount of petrol while idling, it is wise to avoid allowing the engine tc run unnecessarily. Wasteful Friction

Petrol is wasted if there is any avoidable friction when the car or its engine is in motion. Soft tyres cause a drag, so they must be inflated to the pressures recommended by their makers for the weight they are expected to carry, and tested regularly. Maladjusted steering gear is another cause of drag on the wheels, but most common of all is constantly dragging brakes. To the same end a car should bo kept properly lubricated. It is false economy to save on greasing and waste petrol in overcoming friction caused by lack of lubrication. Even the condition of the engine oil bears on petrol consumption, for old sticky oil makes an engine sluggish. Some owners may decide to change the oil in their cars more frequently than hitherto.

To get the most power out of petrol the engine of a car must be in good condition, but the placing of it in proper is best done by a reputable firm. Cylinder compression must be good: the level of the carburettor float must be exactly correct, for if it is the slightest amount too high the consumption of petrol is

affected immensely. Spark-plug points must be adjusted to the gap specified by the car manufacturer. The distributor must be checked in a similar manner, points being properly adjusted and clean and the device capable of operating at the maximum advance position intended.