Will adding a heavier weight oil reduce the oil consumption?

I currently am using Castrol GTX 20w-50


What is the highest weight oil I can use in the 300E without doing damage to the motor?

I am in HOT HOT Miami,FL

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1987 mercedes 300E
1995 e320 conversion(hated the 300e grill)
HID/Xenon (D2S)
Keyless Entry
Monochromatic Paint (Custom Blue)
Smoked Tails
Flat Badged (front)
Debadged (rear)
custom "carbon fiber" console
18 inch HP EVO rims
Sold! Now I drive a Monte Carlo SS
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