This.

No single person or answer is right for every car and driver. I myself don't believe in the oil shear you are talking about, and will use 5w20 mobil 1 without issue. All my cars have always used the factory recommended oil weight mobil 1 and have never had an issue with well over 100k on them.

 

I've seen this thread before...

You should know that the "Ford is trying to save CAFE penalties" theory is coming from someone who claims the moon landing was a government hoax. Conspiracy theories seem to thrive among those on the short bus.

 

I agree. Although I have never used synth till now. Only using Motorcraft synth blend because of the owners manual & warranty.

I have put over 100k on 6 fleet trucks (Ford V8's & V10's) that were run hard and put away wet every day hauling 2-3 tons of coffee, food products, and machines. Dino oil at Ford Dealership. No probs ever. Changed every 3000 miles per fleet mgr.

I have put over 100k on 7 personal rigs - high rev 4's, straight 6's, V8's. Using whatever oil was on sale - only the Lotus got Valvoline or Castrol. My 83 F150 has 253k on it - engine broke a ring at 218. All Dino. All what the owners manual stated. Typically changed at 5000 miles (or at least once a year for ranch trucks).

So regardless what the microscope shows, the practical application in the field speaks for itself.

I mean it doesn't matter how much or how good the Scotch is (or isn't). 80 proof is 80 proof. The results are the same.