hogasswild

Yeah, 2010 GT and 2011 V6 is like apples and oranges. Now a comparison between the new 5.0 and the3.7 is okay due to them both using the advanced variable timing and better ECU. i have been formally documenting my MPGs on fueleconomy.gov and my 93 octane tanks always do better than my 87 tanks unless I end up driving hard or just have worse traffic than normal.

hogasswild

Youre not going to see 20 hp more, but i bet the increase is somewhere between 5-10hp. And the price difference is typically less than $3 a tank, and I am typically able to travel 20-30 miles more on the 93 tank so it just about nullifies the extra cost.

LostBoyz

Yes and no. The knock sensors will advance the spark until you don't have any knock, but that doesn't mean that it will recalibrate itself to a fuel that has less chance of knocking.

Radioguy

Yes, that is true. The "dynamic" calibration done by the new advanced ECU is done in "real-time." It is constantly optimizing the spark for maximum power based on the "blended fuel octane" in your tank. If you have a half a tank of 87 octane and add a half tank of 91 octane(Pushing up the blended octane of the fuel in your tank), the ECU will start pushing the spark advance further - immediately - until it hears the first sign of a knock - generating greater torque and HP. If later you add more 81 octane fuel (pushing down the blended octane of the fuel), and the engine starts to generate a small knock, the ECU will begin to retard the spark untill the knock is reduced - but not to zero. As the spark setting is advanced, the TIVCT will become more "aggressive" as the RPM is increased. So the power add comes from both the spark advance and the TIVCT setting.

With the "tuner tunes," often the operating conditions - like spark timing - are changed so much that the ECU can't adjust "far enough" to accomodate lower octane fuels. So with a "91 octane "tune"" the dynamic range of the ECU controls are not wide enough to handle 87 octane fuel. That is even true for the Ford "performance tune" for the 2011 GT - which apparently makes significant adjustments of the TIVCT to gain over 60ft-lbs of torque at low RPMs - but requires only use of 91 octane fuel.

hogasswild

Whatever it is, it's sweet and I love it. We have great cars.

VistaBlue

Both the V6 and V8's both have adaptive spark, and both will adjust to higher octane. Both will make more power on higher octane - to a point. So far as I recall, the idle tables shouldn't be changed from low to high octane fuel, so the difference you are seeing in idle quality is probably a placebo effect.

hogasswild

That's what I got when I went to Mexico looking to buy Cialis lol.