3.5L Ecoboost Owners - What MPG are you getting?

[ford2017FPIU]

Down to 10 mpg., 3.5L ecoboost, california 87, 89,000 miles. Shop saw nothing wrong with it but I doubt the sparkplugs have ever been changed. That's next on my todo.

 

[mguy13sport]

Down to 10 mpg., 3.5L ecoboost, california 87, 89,000 miles. Shop saw nothing wrong with it but I doubt the sparkplugs have ever been changed. That's next on my todo.

Carbon build up on the intake valves will significantly reduce MPG on a healthy engine. Its a common ecoboost issue as they get older.