I don't think the euro specs change anything oil wise. I would recommend the synthetic especially if you have ticking hydraulic valve adjusters. (they actually are not lifters).

If you are running hot that is not likely an oil related issue and should be sorted out.

Now in my 280e (with mechanical lifters) euro, I was running 10w30 moblil one and caught a slight knock on start up that I suspected was bearing knock from the thin oil running off the bearings, so I switched to 20w50 castrol and that stopped.

Different oils for different motors. You have to be careful. The newer oils don't always work in the older engines.

Synthetics are no panacea.

Tom W

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.