Ford Mustang Forum - View Single Post - What octane are you using in the GT?
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post #16 of (permalink) Old 06-25-2010
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Originally Posted by mustang6767c View Post
Does anyone run 87 consistently? I will eventually run 91 but with my current drive 87 is sometimes a better choice.

Even though Ford claims you can run 87, does anyone believe it may cause engine damage?

By the way I'm purchasing a 2011 5.0 MT with 3.73
It wont cause any engine damage if you are running the stock tune. The stock tune is designed to run 87octaine, its just that you are not getting the "advertised" tq and HP numbers if you run the 87.

Some say the improved gas mileadge offsets the cost of the premium but thats anectedotal and i havent seen scientific proof. Its possible if you are just cruisin down the freeway and dont plan on putting your foot in it that you can save a few bucks and run 87 but come one....its a 5.0, you are going to be getting on to my WANT the premium. I run premium in my 10 just for the extra 10 ft/lb tq.

2011 Shelby GT 500: C&L CAI, Roush GT 500 Performance axlebacks, Steeda 2.65 Supercharger pulley with idler/belt tensioner, Ford SVT Custom Racing Tune, SVT package, Glass roof, Tech package
Gone: 2011 GT/CS Black
Gone: 2010 Sterling Gray GT, Track Pack
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