SirDrums

I just bought an '10 and right in the manual it suggests using BP fuel.

Nuke

Not just in the manual but it recommends it on the gas cap on my '07, too.

Besides BP fuel having one of the better Quality Assurance programs, I'm sure there are some sort of BP/Ford behind the scenes elbow rubbing going on.

Shane Olguin

I see in the manual where it says use BP fuel, but nowhere in there does it say that the car adjusts the performance of the engine based on octane rating.

BL00DSH0T

The owners manual states the 4.6L V8 will run normally on 87 octane regular fuel without damaging the engine, but premium fuel with an octane rating of 91 or higher is recommended for best performance.
It is page 287.

Shane Olguin

That is so ambiguous. That doesn't tell you anything about how the best performance is derived. RTFM doesn't apply here.

FastDEW

There are several and I mean a LOT of places you can find this by going to Google. Ford powertrain engineers have stated it in interviews and it has been in press releases by Ford. Pretty easy to find.

Supafly

This is right from my manual:

Choosing the right fuel
"Use only UNLEADED fuel or UNLEADED fuel blended with a maximum
of 10% ethanol. Do not use fuel ethanol (E85), diesel, methanol, leaded
fuel or any other fuel. The use of leaded fuel is prohibited by law and
could damage your vehicle.
Your vehicle was not designed to use fuel or fuel additives with metallic
compounds, including manganese-based additives."

Supafly

This is right from my manual:

Choosing the right fuel
"Use only UNLEADED fuel or UNLEADED fuel blended with a maximum
of 10% ethanol. Do not use fuel ethanol (E85), diesel, methanol, leaded
fuel or any other fuel. The use of leaded fuel is prohibited by law and
could damage your vehicle.
Your vehicle was not designed to use fuel or fuel additives with metallic
compounds, including manganese-based additives."