Can e15 (88 octane)gas be used in the 2nd generation 3.5 ecoboost?

Using E15 (88 octane) gasoline in the 2nd generation 3.5 EcoBoost engine, typically found in vehicles like the Ford F-150, requires careful consideration. While these engines are often compatible with regular unleaded gasoline with an octane rating of 87 or higher, E15 contains 15% ethanol, higher than the usual E10 blend. The owner's manual is the best source for fuel recommendations, as manufacturers provide specific guidelines for optimal engine performance and longevity. Higher ethanol content in E15 can be corrosive and may affect fuel system components. While the octane rating of E15 aligns with many modern engines, the unique design and tuning of the EcoBoost engine must be considered. Using fuel not recommended by the manufacturer can also impact warranty coverage. E15 might slightly alter engine performance or efficiency due to its different combustion properties. Without explicit approval from Ford for E15 usage in 2nd generation 3.5 EcoBoost engines, it's advisable to use E10 or regular unleaded gasoline to ensure engine health and avoid potential issues.