National Geographic : 1916 Nov
HL ILLS often exact compression and fullpower. i o rfr How much this piston ring full power from seal depends on the oil's your motor. Poor com- body and quality is shown S pression resulting by the hill test. S from wrong oil be- Make This Test. comes quickly ap- Pick out a long hard hill where you have had to parent. change gears. See how far Hot metal rws up you can go on high gear S otmeta i with your present oil. Then hotter. The laboring drain off the oil. Refill the of the engine plainly crank case with the correct says something is grade of Gargoyle Mobil oils. This will probably wrong. cost you less than a dollar. You blame the engine, Make sure that the road but how often the engine and operating conditions blames you - for expecting and speed of the car at full compression from an oil the foot of the hill are which lets power gases es- identical in each trial. S cape past the piston rings. The greater distance IA thorough piston ring that the correct grade of seal is essential to full Gargoyle Mobiloils will 11111111111111111111111111111111111 1111111111111111n nuu1 111 1 11iiii111111111111111 11 11 111111111111111111111111111 1I n I nlllllllllllllllllllllllnllll ll "Mention the Geographic-It identifies you."