everywhere i read the 2013 GT stang has 412 HP yet in the brochure it says you get 420 with prem. gas

is this right do you get more HP with prem vs reg fuel ??

i thought it just burns hotter i used to put it in all my cars every 10th tank to burn the "crap" out of the engine

 

The newer Mustangs have an adaptive computer system that reads the type of fuel the car is running and changes the operation and timing of the engine. Not the technical explanation but it gets the point across.

Do some research on the way each fuel burns and why it does not do much to run what is not recommended.......

 

Higher octane fuel burns slower so it won't provide any additional power benefit on its own and in a motor that doesn't have the compression to support the higher octane fuel it could result in lost power (however small it might be).

The coyote motor runs a comparatively high compression ratio and is able to take advantage of high octane fuels. Equipped with knock sensors, the ECU can roll back the timing (and/or use TiVCT possibly changing cam timing to compensate) when it detects knock allowing the engine to run lower octane fuels when necessary at the expense of power.

However its not the best solution since the motor isn't designed to run on the lower octane fuel so the loss of power is greater than an engine designed to run on that lower octane fuel. This has to do with the roll back ignition strategy which results in increased combustion space and a less than optimal crank angle when the ignition fires.

I'm not sure if the coyote motor uses cam timing to limit knock in that instance, but it would do so by allowing the additional compression to bleed down before closing the exhaust valve which would still allow for a nice tight combustion space and proper crank angle (if used in combination with ignition timing) relative to the fuel being used.