I would be incorrect to assume that a dino 20W-50 and a synthetic 20W-50 work at the same temperature ranges.

The synthetic will indeed have a lower pour point and at the same time provide protection at higher temperatures than the synthetic.

There will always be less friction with the synthetic, minimizing wear, increasing fuel economy, and making cold starting easier.

The synthetic will last longer between changes, thereby erasing the higher cost penalty and also thereby enabling you to pollute the environment less with old oil.

There is zero disadvantage to synthetics and zero reason to use nonsynthetics in the 21st century--no matter when your engine was made.

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Kent Christensen
Albuquerque
'07 GL320CDI, '10 CL550. '01 Porsche Boxster
Two BMW motorcycles