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What octane rating fuel should I be using in my 2014 Ford Focus?

What octane rating fuel should I be using in my 2014 Ford Focus? I have been using 91 octane, but lately it has been running slightly rough. When it was serviced, I asked my mechanic to investigate. They couldn't find anything wrong and suggested I start using 95 octane fuel.

Your car requires an octane rating of 91 RON and, to be honest, the biggest difference in using the more expensive 95 or even 98 RON brew will probably be to your wallet, not the car. Changing to a higher octane rating is not really a scientific way of fixing problems like rough running, and there’s probably another reason for the poor performance.

I’d be scanning the car electronically for a clue to what’s going wrong with it, but bear in mind rough running can be caused by lots of things. If you really want to pursue the fuel you’re using as a potential cause of the problem, rather than change to 95 RON, change the service station you use. Sometimes, a service station can have contaminated underground tanks and this can cause all sorts of running problems by the time the dirty fuel is in your tank. Another hint: If you see a fuel tanker delivering fuel to a service station as you pull up to refuel, find another service station. The fresh fuel being pumped into the underground tank will stir up all sorts of nasties that would otherwise settle at the bottom of the tank. By filling up immediately after the station’s tanks have been filled, you stand a good chance of buying a tankful of dirty fuel.

 

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