Or modifications/software changes. They have become pickier and more proficient at detecting these.Warranties don't cover abuse.
FWIW the Ecoboost is a fairly new design. The big difference is with the placement of the fuel injector. It's called direct injection. The injector is mounted in the cylinder head and sprays directly into the combustion chamber. Fuel pressures can hit 3000psi. The intake pump delivers fuel to a mechanical pump which typically is camshaft lobed powered. Be very careful with engine lubes. Just to complicate things the wonderful ZBTs used in oil have to be eliminated for the catalytic converters to survive.
I would give this relatively new technology some time to improve. It has some great benefits but do you want to be part of the test group. Not me.