Does the type of gas i put in affect the time to have the gas engine running in order to meet the emission standard?

Maybe I have a totally wrong concept: The lower the gas, the "dirtier" the gas will be, therefore the gas engine has to run longer in order to meet the low emission standard. Thus, the EV mode will not kick in as early as I am using higher type (89) gas?

I used to use type, i just changed to 87 and I realize that the EV mode kicks in at the later stage. I am confident that my driving habbit is the same though.

What do you think?