Ferrari 275 GTB - 1965 - oil

For the engine: Standard 20W/50 wt.
For the transaxle: Synthetic 75/90 or 80/90 wt. plus a tube of limited-slip additive.

S6721A was a factory fill made by Shell for Ferrari. It was standard 90 wt Spirex EP with a limited-slip additive already mixed in. I researched this with Shell in the early 1970s.

 

I only use Brad Penn 50 wt. in mine. It works perfectly.

 

True, zinc additives are supposed to be important.
I use Valvoline Racing 20-50.

john

 

Prance, John: Good comments, I do also add ZDDP to my Castrol GTX. However, I believe the Ferrari engines really do not need it. The engines that really require the zinc additives are the US V-8's running flat tappet camshafts and high valve spring pressures. The Ferrari roller cam followers should not need the zinc additive, though I use it as cheap insurance.

 

For what it's worth this is what we've used for many, many years and miles...

Gear Racing Oil : Shell Helix Racing Gear Oil 75W-90 @ Shell Racing Solutions Australia
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Hi Dyke, where is it exactly where zinc plays a useful part? I thought it was where two metallic pieces rub against one another, like cam lobe rubbing against the tappet in the DOHC engine. Is that it?

john