first off i live in Houston, the premium in my area is 93. and i believe most of these dynos and tests have been Cali where im assuming the premium is 91. what if any power increase would there be when running 93 octane?

 

10hp 10tq in the 4.6L

 

Kind of hard to say. Ford claims the Copperhead continously seeks to maximize timing which would make me believe it might take advantage of extra octane like an LSx. I dont belive it simply has "dual maps" like a Bullitt or 2010.

The SAE J1349 Test resulted in 416/394 on 98 RON Fuel (Roughly the same as 93 AKI Pump Gas). So while it may not help it certainly didnt hurt. Ford chose to derate the engine by 1% which is allowed by SAE.

The engine was not SAE certified on 91 AKI Fuel. Ford however claims it will make max rated power on 91. Does that mean it makes 416/394 or 412/390 on 91??? Or put another way does it make 4 hp and 4 t less than it makes on 93?

 

Yeah I live in tx too. I feel a little more power on the butt dyno with 93 vs 87. But im guessing the computer knows the 93 is better then Cali cat pee 91 gas?

 

I'd say on a NA engine it would be minimal for 2 octane points.

I don't recall the exact number, but I think Ford said the 5.0 can run on 87 octane but it would drop power to like 406 hp.
So that's 6 hp for 4 octane points.

So, like Gene stated, the 2 octane point difference from 91-93 might be worth 3-4 hp at best.
On FI cars that have adaptable ECU's that will add a bit more boost to the equation (like on my 335i) the difference between 91 and 93 was nearly 10 hp. More like 15 if the car was tuned.

What I'm curious about is what Meth will do for the 5.0

 

wow. im actually impressed with that, cause i would of thought it would lose more power than that if (and that's a big if ) the 5.0 would ever be fed 87 octane.

 

With your custom tunes, I'd say going from your 87 custom to your 93 custom would yield roughly 5-8 RWHP.