Just so you don't confuse some that don't know any better, the flashpaq retunes the engine to make more power, and it does that "pushing the envelop harder" making more pressure and higher temps in the cylinder that require more anti-knock rating from the fuel, that I talked about in my earlier post.i use the 91 octane tune on my flashpac and run 91 most of the time its made a big difference in my 4.7
What Model Year is your Commander? Cause it may have changed from year to year. BUT, totally agree with the point, check the owners manual and use what is recommended.I have a HEMI and the manual states they do not recommend premium and 89 is recommended.
For the V6 and 4.7 models 87 is recommended.
I also recommend sticking with top tier gas stations like Shell, Exxon, and Mobil. I've had a significant drop in fuel economy with cheaper gas brands.
Use what the owners manual states. Typically 87 unless otherwise statedDoes the grade of gas make a difference in a 4.7 Commander? I never really learned what the difference is in general.
Also, does anything higher than 87 even work in the 4.7 flex fuel commander?