Ford Fusion Owners Manual - version 1 (3/2016) states on page 153:
"Choosing the Right Fuel
We recommend regular unleaded gasoline with a minimum pump (R+M)/2 octane rating of 87. Some fuel stations offer fuels posted as regular unleaded gasoline with an octane rating below 87, particularly in high altitude areas. We do not recommend fuels with an octane rating below 87.
For vehicles with EcoBoost engines, to provide improved performance, we recommend premium fuel for severe duty usage such as trailer tow.
Do not use any fuel other than those recommended because they could lead to engine damage that may not be covered by the vehicle Warranty. Note: Use of any fuel other than those recommended can impair the emission control system and cause a loss of vehicle performance.
Do not use:
• Diesel fuel.
• Fuels containing kerosene or paraffin.
• Fuel containing more than 15% ethanol or E85 fuel.
• Fuels containing methanol.
• Fuels containing metallic-based additives, including manganese-based compounds.
• Fuels containing the octane booster additive, methylcyclopentadienyl manganese tricarbonyl (MMT).
• Leaded fuel (using leaded fuel is prohibited by law).
The use of fuels with metallic compounds such as methylcyclopentadienyl manganese tricarbonyl (commonly known as MMT), which is a manganese-based fuel additive, will impair engine performance and affect the emission control system.
Do not be concerned if the engine sometimes knocks lightly. However, if the engine knocks heavily while using fuel with the recommended octane rating, contact an authorized dealer to prevent any engine damage."
Sooo, the usage of high-grade gas only drains your wallet and can potentially harm your auto - it's not recommended. Note the bold/red portion.
And as for tire pressure, OEM Michelin tires run just nicely at 40 PSI as the OP states he does. While under-inflated tread can blow out, so can dangerously over-inflated ones. Your pressure over-inflates too much.
Larry - aka Cobra
Big Red: 2017 FFH SE, Ruby Red, Med Light Stone leather
602A SE Luxury Package, Park Assist, Adaptive Cruise Control w/stop & go
Driver Assist Pkg (lane keeping, BLIS, auto high beams, rain-sensing wipers, heated steering wheel)
My additions: WeatherTech lasercut floor mats, in-channel wind deflectors (dark smoked),
Steeda strut tower brace, Steeda rear sway bar, Steeda hood struts, Ford donut spare,
blacked out grille
Summer rims/tires - 17" Verde Regency rims with OEM tread
Winter rims/tires - 17" OEM rims with Goodyear UltraGrip WRT Ice