REAR REFLECTORS

Sun (Auckland), Volume II, Issue 360, 22 May 1928, Page 7

REAR REFLECTORS

MEANING OF REGULATION Several people have written to me making enquiries about the rear reflectors required by the new regulations. As quoted in “The Sun” last Tuesday, the regulation states that the rear reflector may “form part of the tail light,” and must have “an effective reflecting surface not less than two square inches.” It was pointed out last Tuesday that what constitutes “an effective reflecting surface” may have to be decided by the courts, as one magistrate may hold that a red tail light is sufficient, while others may not. This question has been taken up by the secretary of the New Zealand Motor Trade Association, with the Public Works Department, and it appears that the reason for the regulation I is that, in the event of a tail light fail- j ing, the red reflector required under the regulations would act as a reflector of the headlights of an overtaking vehicle and avert danger. From this it would appear that the ordinary flat red glass of a tail-light, if not specially cut as a reflector will not satisfy this regulation, and in all such cases a separate reflector must be fitted before June 1 to oomply with the regulations. 150 TESTS OF CAR GENERAL MOTORS’ METHOD How will the motor-car of to-day act under different conditions? That’s the question that is discovered on the 1245-acre track near Detroit which belongs to the General Motors Corporation, and which is known as their proving ground. There, all different makes of cars are put through every imaginable kind of test, from the most gruelling to the most ordinary, and all results are carefully checked up and tabulated. A large corps of engineers is busily engaged in an effort to determine just liow cars react to different conditions and different treatment. Certain parts of a car wear after being subjected to various tetfts. How can mechanical details be bettered? How can vibration be lessened? How can wind resistance be cut down? How can this and that be improved upon so that the automobile can be constantly made better? These are the problems that the engineers endeavour to solve and the proving ground is their laboratory. Here with delicate instruments they check up on every detail. On this large* tract of ground there is practically everything to test the stamina and endurance of a car. Small, steep and medium-sized grades, a banked speedway for testing high speeds, hairpin curves, mud holes, water baths, concrete roads, unimproved dirt road, tarvia roads, gravel roads, deep sand roads, skidding pads —everything that a car is liable to meet under any conditions. And here, on all these different kinds ; of roads, will be seen cars flashing past constantly every day of the year —all intent on proving exactly how

fast a car will accelerate, what causes wheels to shimmy, how much petrol and oil are consumed per mile, how fast a car will go, whether four-wheel brakes • will stop skidding, ability for hill climbing, and so on. The car is first sent out to be driven for 2,000 miles at the specified rates of speed so that it may be broken in for the sevesre tests that come later on. At 2,000 miles the car is taken to the shops and tuned up for its first tests. Here it goes through the regular procedure or overhauling that any dealer gives a. car after it is broken in—valves ground, brakes examined, and lubrication checked. Now comes the 150 tests that determine the stamina of any car. The main ones are acceleration in low and intermediate gear; acceleration from 10 to 25 miles an hour in seconds; acceleration from 10 to 35 miles an hour in seconds: maximum speed for flexibility; maximum speed; hill climb; 11.65 per cent, grade, with 4501 b. load, starting in high gear at 10 miles an hour —20 miles an hour —30 miles an hour; fuel economy at 10 miles an hour, 15, 20, 25, 30, 35, 40, 45, 50 and 55; vibration and noise at driver’s and passengers seats at various speeds; steering effort; cold weather starting; carburettor mixture temperature; distance stop; clutch pedal pressure to throw out, to hold in; time to change tyres with the car tools; time to grease and oil the car; time to wash and polish the car; fuel consumption on endurance runs; overall cost of operation a mile of test; ventilation and humidity inside of car at various speeds; area of clear, vision; angle of *Hear vision; and light reflection at driver's seat.