mdg

Ok, the manual says that 87 octane is recommended, but Ford's website says Unleaded Premium. Which one is it? I love the cost of 87 after years of putting 93 in my 2007 with the Vortech. Just want to make sure I'm using the correct "recommended" fuel, thanks!

Cruzinaround

If you're stock.....87 is cool.

If you're gonna performance tune your vehicle....higher octane will have better results....or if you can find 87 octane with no ethanol in the mix....then you'll possibly see better mileage. Most of the stuff you find is 10% mix of Ethanol at the pump.

Csrt4to5.0gt

You only get 402hp and 377tq on 87 and the full 420 and 390 on premium. All instrumented performance tests of the new 5.0 were done on premium so premium is recommended but not required. So it's your choice. Every car that I've owned that recommended premium got premium but that's me. You can get custom tunes to run your car on 87.

Csrt4to5.0gt

Are you referring to the 5.0 in your pic? My manual says 91 is recommended.

ModBargains

It's worth the extra oomph if you know what I mean, to use 91 octane. I only specifically use 91 octane either at Shell or Chevron ONLY. I might be picky, but at least I know I'm getting top tier quality gas. ARCO or any other lower tiered fuel just wont cut it.

Andy13186

with stock tune it makes 10 hp more with premium

anyway i use 93 octane, and have a 93 octane tune

MrSandman

The engine adjusts to the octane. Use whatever you prefer. As others have said, there is a HP increase with higher octane, but it's not like the car will be slow with 87/89. You will get better MPG with ethanol-free gas, if you can find some.

Nuke

Higher octane on the 5.0 stock tune will net you some additional RWHP but not as much as a good custom tune will. And running 87 octane won't hurt a thing. As stated earlier, the 5.0 will adjust for different octane.

outceltj

I find it hard to believe that u will gain 10hp by using 93 compared to 87 or 89. If you don't hear spark knock then use the lower grade. And if u want some more testosterone then get a custom tune. And really how much of a price difference is lower grade compared to 93. 20 cents so if u go with the premium u might be paying 2 dollars more for every full up. So what exactly is the purpose of this thread

Art161

You really are missing the point of this thread. The point is that you can use 87 octane without spark knock because the engine adjusts to the lower octane. I find it hard to believe that you don't believe there is a 10 hp gain using premium over regular in this engine.