Great response just received from Castrol North America. Faith has been restored.
"Further to the below, we apologize for any confusion and will clarify.
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Castrol GTX MAGNATEC and Castrol EDGE formulations are different but both Castrol EDGE and GTX MAGNATEC formulations contain the intelligent molecule in the ILSAC /API SN PLUS grades. Castrol EDGE adds Titanium, our patented titanium molecule technology that has demonstrated anti-wear and friction reduction performance, to the mix so both products are great for stop and go engine operations.
In Castrol GTX MAGNATEC we specifically focus on warm-up wear as the distinctive performance feature of the brand.
From the standpoint of overall motor oil performance, Castrol EDGE is designed to meet tougher performance standards with specific focus placed on high temperature deposit control, maintaining viscosity under high shear conditions and high temperature oxidation performance.
Both Castrol GTX MAGNATEC and Castrol EDGE provide the same excellent wear protection as measured in standard industry testing.
Castrol EDGE is our premium product line.
Castrol Consumer Relations"