What fuel do you run in your EcoBoost pickup? (not HO)

Lantley wrote:

Grit dog wrote:
^ Been like that as long as I been on this forum.
But I do enjoy the off the wall theories like engines taking tanks of fuel to adjust to octane.....

The real engine gurus are those that know more than the manufacturer.
They know the owners manual is full of wrong statements that are to be ignored:S

As I said in the previous threads, it is not a matter of saying you know more than the manufacturer, but rather your perception of what the manufacturer is stating here. One may perceive that Ford is stating that you have to use premium fuel when towing while others percieve what the manual states is that you can use it if you want more power, but it is not necessary to engine longevity.

If you look at all the owners manual for Ford, they state the same thing for all of their multi-fuel engines that use cam phasers and direct injection that can adjust time on the fly. Heck, they even state the same for engines they don't have direct injection like the 6.2L and I would bet that they would say the same for the new 7.3L gas engine.

Parker.rowe, you went into a little more detail than I would have or wanted to, but you are correct. However, I would not call it learning because that infers the computer gaining knowledge it did not know on it's current maps. Everything the ECU does is preloaded into the ECU it is just the factor of reaching those parameters to achieve the desired outcome so it isn't really learning, it is just using what is already programmed into the ECM.

Today's engines use sensors with a wider band, and things like cam phasers and direct injection that Ford uses allows them change timing instantly compared to older electronic fuel injection systems.

I haven't been inside a Ford computer (but I have tuned others) but lots of them do readjust the timing.

And sometimes it can take time to get the full benefit.

They do have set "base" maps for timing...fueling usually stays the same, based on load vs. rpm. It gets trimmed both instantly (STFT) and then it slowly adjusts the long term trims (LTFT) to bring the short term trims closer to 0.

This is done based off the 02 sensor readings.

Timing has a modifiers in the ECU's I have been in. If it see's no knock it will move the modifier closer to 1 (100%). That means it will use 100% of the commanded timing for that load/rpm. The modifier never STARTED at 1 in the ECU's I tuned though. It starts lower and slowly (and safely) moves up...but it will drop instantly if it see's knock to prevent damage. It will also reduce boost as well if it needs to.

The modifier gets multiplied by the base timing to get the commanded timing. So if it below 1, you will get less timing than the max in the table.

That way, you can run at 87 and it will be fine, but if you use 93 it will creep up the timing (and power).

So, I would call that "learning". But maybe there is a better term. Manufactures all have slightly different strategies.

Not sure what ford's is, but I have seen dyno tests comparing 87 to 93 and showing gains. So it seems possible that there are changes made. Octane doesn't make any more power..but the ability to run more timing does.

You may not see a difference towing or around town, if you already had plenty of part throttle power. But you would see it flat out on the dyno or at the drag strip.

Also, it does not have any octane sensors...it doesn't KNOW the fuel you put in is 87 or 93. Although with flex fuel vehicles it can detect the change to e85 and such.

That requires changes to secondary fuel and timing maps.

Probably more info than some people wanted, but there it is. :)

Defer to Shiner, he has much more current knowledge

Mine comes from trying to figure out they why my MPG went down during seasonal changes to fuel blend

Those ECU's had memory's that could be wiped clean with the removal of power for x hours or so. Not so with today's onboard memory

ever since the advent of knock sensors, their ECU's backed off timing "NOW"...that is the whole purpose and usage of a knock sensor

Grit dog wrote:
^ Been like that as long as I been on this forum.
But I do enjoy the off the wall theories like engines taking tanks of fuel to adjust to octane.....

The real engine gurus are those that know more than the manufacturer.
They know the owners manual is full of wrong statements that are to be ignored:S

^ Been like that as long as I been on this forum.
But I do enjoy the off the wall theories like engines taking tanks of fuel to adjust to octane.....

Speaking of premium gas. I remember when going from reg to mid to premium was only .10 higher for each jump. Now it's (local station) +.17 for mid and +.32 for premium.
One other station has it @+.20 for mid and +.30 for premium.
Had a diesel for 6 years and didn't really notice the fluctuation until I got my Ram 6.4.

Wow,has the forum gotten so politically correct that I can't even say r e t a r d (even though it is a legitimate term for reducing or holding back engine power) without it being blocked?

BenK wrote:
Takes more than one tank of higher octane before the ECU will relearn HOW2 manage

Even longer if driven gingerly TRYING to get higher MPG

You must demand power mode often and for long periods of time

So the ECU will relearn to generate a new fuel mapping table(s) for Power Mode, which will also affect MPG

Maybe the OEM has limited the level of Power Mode allowed. So even aviation fuel won't mske a difference and if so, a tune will be needed

Plus there are other attributes in play. Main two are thermal limits and the auto trannys computer algorithms

The computer does not learn anything and the change in output would be instant if you completely cleared your tank of 87 before putting in 93.

The change in power output is based on how much knocking the knock sensor detects. If it does not detect knock then the ECU will allow the valve/ignition/fuel timing to be advanced until it detects knock. When it detects knock then it will pull or ****** timing until it does not detect knock anymore. The computer is constantly pulling/advancing timing so if the octane of the fuel allows it to advance timing then it will do so immediately.

In regards to learning, the ECU does not have the capability to learn. Inside the ECU are a bunch of fuel maps that determines how much fuel/timing to advance/****** based on these predetermined fuel maps. The ECU uses the data from all of its sensors to know what to do based on set parameters. Basically, the map would say that if sensor A, B, and C are reading this, then you valve timing should be X, your ignition timing should be Y, and your fuel delivery should be Z for the corresponding throttle input and rpm. These maps never change unless someone( a tuner) re-flashes the ECM with new maps.

The reason why most do not feel an instant change has more to do with the fact that they probably still have 87 in the tank so they "feel" a gradual change over the course of a few tanks. The best thing to do if you want to see a difference is to run the tank of 87 as low as possible and the put in 93.

SHO, might take advantage of the higher octane, F150 won't.

WRT to better fuel economy, higher octane fuel has LOWER Btu's of energy. If an engine is tuned to take advantage of the higher octane, then it will realize increased HP.

I run 93 in my Charger and challenger, they are both tuned to 93 octane. F150 gets 87... and besides when towing, even if there was a increased fuel economy, it most certainly wouldn't make up for the cost. I don't need a hot rod when towing :)