I have a 2018 F150 with the 5.0 V8 engine and 18000 miles. I asked the service guy at the dealership about switching oil from Synthetic Blend to Full Synthetic. He told me that Full Synthetic Oil would have bad for my engine. Why would it be?
You should have asked why. Sounds like BS to me. Most new cars specify ONLY full synthetic oil.
Even if the manual recommends synthetic blend, synthetic is always better for the engine. He is talking BS.
If the vehicle has used conventional oil for its lifespan then the consensus is to continue using conventional. The reason for this is because synthetic oil has a high flow rate at the same viscosity as the same conventional oil. So say you use 5W-30 conventional oil. The same 5W-30 oil in synthetic flows better. This can result in the premature leaking of various engine seals especially on V8 engine assemblies. As conventional oil gets phased out the consensus among mechanics will most likely be to stick with synthetic oil as the vehicle now come with synthetic oil in them. Scotty also has a video on his channel about this which you can watch and review for yourself.
