More power with >93 octane?
- Thread starter Erich
- Start date
In the tune, the knock sensors can add timing when they see no knock. The knock sensors can only add so much timing. So, If your pcm is seeing knock on 93 and its pulling timing, then yes, higher octane would help, but If your on 93octane and your seeing no knock and the pcm is not pulling timing, then higher octane would be a waist, unless you have a custom tune.
Chris
Chris
Well put Mastwolf
I would however think that Ford would program the pcm's base timing values around 93 octane to begin with however. Many areas of the country have this as their premium swill. Area's like Colorado where I'm at have only 91.
But yeah, what mastwolf is saying is 100% correct. Don't expect to gain power from adding more octane than what's needed. At least not without specific tuning for it.
The effects of this can also be somewhat detrimental to engine life and performance. Although probably not as much of a problem with today's engine technology, running octane beyond what's needed for the engine can create fuel burn issues. Over time this can aid in development of carbon deposits on the piston face and valves. These carbon deposits can develop hot spots that pre-ignite the fuel mixture. This in turn causes an "octane tolerance" in which you have to have that higher octane fuel, but without much of the benefit.
Edit: I'm an idiot, I didn't see your > in the title post and thought you were talking specifically about 93 octane.
But yeah, what mastwolf is saying is 100% correct. Don't expect to gain power from adding more octane than what's needed. At least not without specific tuning for it.
The effects of this can also be somewhat detrimental to engine life and performance. Although probably not as much of a problem with today's engine technology, running octane beyond what's needed for the engine can create fuel burn issues. Over time this can aid in development of carbon deposits on the piston face and valves. These carbon deposits can develop hot spots that pre-ignite the fuel mixture. This in turn causes an "octane tolerance" in which you have to have that higher octane fuel, but without much of the benefit.
Edit: I'm an idiot, I didn't see your > in the title post and thought you were talking specifically about 93 octane.
One would imagine 91 octane is the target-based on the fuel available around the country. In MD, it is mostly 93 except sunoco which has 91 (I think) as well.
I was just thinking maybe there is no need to cap it the timing-a little more octane a little more timing. It would just back off from detonation. But for robustness, it makes sense that there is a limit to that.
Erich
I was just thinking maybe there is no need to cap it the timing-a little more octane a little more timing. It would just back off from detonation. But for robustness, it makes sense that there is a limit to that.
Erich
So a stock 2011/12 5.0 will not produce more power when filled with 93 octane vs 87?
I believe the actual horsepower number that ford rates 87 vs 93 octane is written in the operators manual in your glove box. Im not next to mine right now, but it does say there will be a gain, something like 6-10 horsepower i believe.
The manual also recommends you to use BP fuel, funny thing is i always use BP. Picked up a rental Ford F150 at work, the fuel cap even said to use BP. I was surprised they are so stringent about it.
I havent had a chance to study my Mustang manual, but i had Read the 2011 Raptor manual for a work project. It clearly states that the HP rating on 93 octane is the as advertised 411hp. With 87 octane, the HP rating drops to 400hp. It would be my guess that the 11/12 5.0s would see a simlar drop off using 87 octane.
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Ford has some kinda tie to BP. Not sure if they own part of it or what.
I think it had something to do with BP holding out as long as possible to do the whole 10% ethanol in the fuel.
You are all way over thinking this.
Stock tunes = Relativity safe on all fuels (87 -93)
Ford will recommend "Premium" notice how they dont say "93" because they know In a car that was designed around a goal of "412 HP SAE" they used Premium 93 fuel. But they also know that Joe Blow will go and put 87 in it, so thats why we have Knock sensors that ADD timing into the mix. The spark will start out at a mid point, and if there is 87 in it, and it knocks, it pulls some, if not, it will add it till a certan point, ether A) it sees knock or B) it reaches the max alowed spark.
Now there are lot of other things that go into play, 87octane on a hot day or nice cool day, location and altitude have alot to do with it. 87octane in FL might withstand different timing than in Colorado, there for making different power.
Chris
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