if it doesn't ping then your probably fine. if it starts to ping... u need to go to a higher octane rating. but the question begs to be asked... if u could afford the car, why can't u afford the recommended fuel?

 

If you care not about performance I'm not sure why you bought this car... It's no Ferrari but if you want a cheap economical daily driver with no regards to performance there are MUCH better choices out there.

To answer your 89 octane question - I don’t use it but I suppose it's not going to “hurt" because the ECU will sense the ping and pull timing and you will be driving a slug in a relatively conservative non-performance mode. If you don’t mind that then again, you should have bought another car.

I wish I could get 93 here... But I have several breather mods and ECU flash... 91 is the best gas I can get and even it prevents peak performance sometimes.