Has anyone experienced a slight "hiccup" when their 2015 Mustang GT with Automatic transmission is in Sports Mode and you did a hard 0-60 acceleration from a stop? The hiccup occurred at the very end of 1st gear, just before entering 2nd gear. It seemed almost as if the engine may have redlined for a split second and lost power, but recovered quickly. It did this the first three times out of 5 tries, but not the last two times. The only changes that I made to the car were the addition of the Ford Performance Touring Exhaust (aka Borla). I usually run 89 octane, but put 93 octane in for this run. 3.55 ratio differential.


Could the engine still be "adjusting" to the higher octane that I decided to use? I drove about 40 miles on the higher octane before I tried these fast runs... It did not have this issue when in regular mode but with the transmission in "S" mode. Other than the steering, is there any difference between using the "Sports Mode" or transmission in "S" mode...?


Thanks.

 

Many vehicles either have a fuel cutoff or an interruption of the ignition at or near redline to keep the engine from exceeding a maximum safe RPM. I've hit that mark in other vehicles and the issue you described was similar, a momentary stumble.

 

Agreed. I think you're hitting the fuel cutoff point. Same thing happened to me the other night, and I recall seeing the whole speedo light up red. It took me by surprise a bit since I expected it would just shift right before.

As to your question about the Sport modes, I do believe there is a difference between S and S+, but I don't know what exactly and haven't been able to find much documentation on it.