Recommends 95 octane - What if i use 91??

price of fuel can be a bit steep nowadays.

I have a 2009 euro and the fuel cap recommends 95 octane...

What if i just use 91 octane?

Can it cause any 'real' dramas?

The car is tuned to 95 octane. It may run lean, can knock at high revs with lower octane fuel. SO DON"T. A full tank cost like 5-7 bucks more. Buy 1 less coffee a day or less maccas. And god sake dont use E10!

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.