See how a heated piston head reveals the secret of

SHELLM MULTIGRADE

Now you can see why new Shell X-100 Multigrade is the oil for your car. You can see, too, why this revolutionary oil actually makes your engine cleaner, more efficient, more powerful.

New Shell Multigrade is the result oi a remarkable technical break-through—the discovery of a combination of non-metallic. additives providing all the properties required in a Multigrade Oil but without the disadvantage of metallic ash being left in the combustion chamber. New Shell Multigrade leaves no ashy deposits.

Why engines lose power. Apart from mechanical deterioration, engines lose power simply because of the accumulation of combustion chamber deposits. Part of these deposits is left by the lubricating oil. Every modern motor oil except Shell X-100 Multigrade contains metallic additives. When these additives burn away they deposit metallic ash in the combustion chambers and on the valves. As these deposits build up your engine loses power and efficiency, performance falls off, fuel bills increase. How Power is regained with

new Shell X-100 Multigrade. Combustion chamber deposits are in a continual state of change: existing deposits gradually disappear and new ones are formed. With new Shell Multigrade no new ashy deposits are laid down. Your engine becomes cleaner and power is regained. Cold starting is easy on Shell X-100 Multigrade

Because of its Multigrade propertiesnew Shell Multigrade is more fluid than ordinary oils when the engine is cold. On cold mornings your car starts easily. Your battery and starter are spared excessive wear. New Shell Multigrade circulates immediately to all the working parts, giving your engine complete protection right from the word go. Reduced wear on engine, starter and battery ;reduced fuel bills, better lubrication. ENGINE CLEANER • POWER REGAINED

These are actual photographs of a laboratory test witnessed by Shell dealers.

On the right, you can see the metallic ash left when an ordinary highperformance oil Is dropped onto an electrically heated piston head. Above, the non-metallic additives In new Shell X-100 Multigrade burn away leaving no ashy deposits.