Quote:
Originally Posted by epjfsa
Unfortunately the rule of thumb is that this ISN'T true. A typical vehicle with a fixed engine map isn't able to produce any more power (or operate any differently) on higher octane fuels. Meaning the ECU or perhaps even the physical design of the engine can only advance spark or make other adjustments to maximize power on 87 octane.
Like I said, it's uncited and is therefore not proof of anything. I could have added that line to Wikipedia myself out of the blue, so without citation we have no idea what the original source is. We also have no A:B dynos on higher octane fuels to suggest that it's true. I've put a few tanks of 93 in and though it does seem to make a difference, the placebo effect is very strong!
|
Unfortunately, dude, you don't know what the Hell you are talking about.
ECUs have been adding or pulling timing in response to detected or inferred octane for like 15-20 years, now. What else do you want? It's not like compression will be variable. That technology only came out within the last year, from Infiniti.
So stop running your ignorant mouth. Hell, you don't need experience running hundreds of advanced ECUTEK logs and tuning your own Mazda MZR engine (a 2010 car, from 2006 or earlier design at that) to have proof. Just check out the Toyota manual from the 2006 Tacoma:
From the 2006 Tacoma Owners Manual
"OCTANE RATING
2TR- FE engine - Select Octane Rating 87 or higher.
1GR- FE engine - Select Octane Rating 87 or higher. For improved vehicle performance, use premium unleaded gasoline with an Octane Rating of 91 or higher."
The 1GR-FE pulls less timing from theoretical optimum, the higher octane you use, up to about 93. Or rather, the inferred octane, based on how progressively long it can go without detecting significant knock.
It also adjusts the vvti tables based on the same, such that when you're on 91-93 octane, it broadens the torque curve a bit, so max torque comes in a few hundred rpm sooner and lasts a few hundred rpm longer. There are literally hundreds of tables inside modern ECUs. Nothing "fixed".
These principles are the exact same ones leveraged by tuners like Vivid, who if you couldn't read, actually offer various tuning levels based around the octane you use, too lol.
Btw, to give you an idea of how long ECUs have been "advanced", my 2010 Mazda with the 2006 original engine and ECU design, was still capable of flashing to RaceROM, which let me use the Cruise Control speed switch to toggle between various tunes on the fly, with the rev counter needle changing from 1k, 2k, and 3k on the fly briefly, to indicate whether I was in "bad gas", "race tune", or "data logging" mode.
