Recommends 95 octane - What if i use 91??

[DakDak]

Nope.

But you'll notice you'll spend more on E10 even though its cheaper because it doesnt last as long as the good stuff.

Believe me I've tried.

Your stock ecu can make small changes to the timing to adjust for the lower octane fuel.
This should be enough to negate any engine knock, when you floor it in bursts e.g Overtaking.

I wouldnt want to stay in the above 4000 rpm range with poor quality, lower octane, fuel.

You will most definitely feel a loss in power.