First off, it's a Ford cyclone, the duratec is the older 3L engine.
Second, Ford doesn't make engines. The duratec 3L v6 is a Mazda K engine, the duratec 4 cylinders are a rebadged Mazda L engine, and the Ford cyclone 3.7L you're thinking about is a Mazda MZI engine. Ford owns rights to manufacture all these engines under their own name to make it look like those engines are theirs.
The ecoboost 3.5 is a Mazda MZI turned into a turbo engine by Ford. The ecoboost 2.3 is a Mazda MZR engine with fords own cylinder head and ECU. The Ford CD3 chassis is the Mazda 6 chassis and the CD4 is simply an evolution of that same chassis.
So yes, nearly all of fords car ride on a Mazda chassis and have a Mazda engine In it. Don't call it a "Ford" engine because Ford DID NOT make any of these engines.
Most cars used to run 5w30. Then they switched to 5w20, and now they use 0w20. It's just thinner oil to satisfy the strict CAFE regulations. It might only make a 0.2 mpg difference per car, but add that all up and each manufacturers (Corporate Average Fuel Economy) is improved considerably. In reality this thin oil increase drivetrain clatter and results in less hot-weather/aggressive driving protection. All these Mazda engines are an old design which means you can easily run 5w40 if you wanted to. I use 5w30 liqui moly (very good quality oil) with great results.
Mazda makes very good engine technology, andFord can't design anything which is why they partnered up. The new Mazda skyactiv engines are essentially the older design Mazda L engine with the new cylinder head, higher compression pistons, new exhaust manifold, direct injection etc. But this isn't a strike against Mazda in any way because their L engine was very futureproofed from the start, so with all these changes it continues to provide competitive fuel economy and is really a great sounding, nice revving motor.