I've noticed now that even the premium octane (mostly 91 here) now has 10% ethanol. Is that going to be a problem now with my 91 Max tune on the TP Xcal2???

 

I don't know myself, here in Richmond, Va. there are doing the same.. All grades will have a 10% blend of ethanol.....
Maybe Mike will chime in on this question.....

 

The 10% ethanol blend is still going to work because the octane will be there. The BTU content will be less so fuel economy & power will suffer a little

 

Hopefully you all will take careful note of which jacka$$es voted for this mandatory ethanol blend in your state and vote accordingly in November. This also came up for a vote recently in Wisconsin. I called my state rep and told him that ethanol raises havock with marine engines with big time corrosion. I further explained to him that he could count on everyone who owns a boat or works in the marine industry to vote against him in the up coming election.

I guess something worked as this mandatory ethanol bill got voted down and we still have good 93 octane available.

enb

 

Great question Khrobar. I am so close to empty now on 87 I'm gonna use 91 with tune tomorrow

 

only a matter of time tho as it is now federal law to use ethanol as the additive.

 

And speaking of refilling, how far down do you run the tank to switch octane, and tunes on the XCal2?? I will probably give TP a call this afternoon to find out.

 

I ran down about 35 miles after the "Low Fuel" warning chimed. Filled 'er up with 91 but not really a chance to get on it. The 1-2 shift gunned through about 45 is very impressive though. I know there is probably a gallon or so still in the tank and was still in the fuel lines after fill up but NO detonation or anything

Superb product.

 

I'm Sooo glad this topic came up, as it is indeed a hot one.

I completely agree with "One Ford Truck's" attitude on this - find our which jackasses in your state voted for the mandatory 10% ethanol, and fire them by getting out and voting against them.

Now I would have no problems with a pure ethanol (or better yet, methanol) fuel system, but that won't happen until we run out of oil, or gas hits $10 a gal,on - our politicians are darn near all just that stupidly self-motivated by their lobbyists pouring money into their campaign warchests - meaning we need a complete overhaul of the electoral process to take the money out of it.

Anyway, sorry to get off on a rant.............the answer many of you are looking for is NO, your do NOT need tuning changes - your PCM will be able to keep up with this change no problem, the 10% ethanol-blended fuels have about a 14.2:1 stoich point and the O2 sensors will automatically start switching there instead.

The main thing is that you simply lose a little bit of peak power and fuel mileage due to the lower BTU content of the portion of the fuel that is ethanol.

And by the way - for many years now, it has been a *requirement* that the fuel systems of all vehicles here in the US be able to run on a 10% ethanol mixture - yes, alcohol-based fuels are indeed more corrosive, and they have about half the BTU content of "normal" gasoline - but they also have a high octane number, and if tuned for to the nth degree, we could get a 20% power gain from it - why do you think Indy cars run on methanol?

So all of you can rest regarding is it OK to run your custom tuning on 10% ethanol blends, you've been doing it for years & years already, every winter - you just don't make quite as much power or get quite as good fuel economy, basically.

I hope that helps,

 

BP have released to selected outlets in England their new BP102 Ultimate.

That 102 octane rating is the RON number and MON is 90 so it works out at
96 octane at a figure comaprable to gas in the US.

Only problem is that they are charging $16.00 per US gallon over here for it

I may need a "special" tune off MIke though

 

If the ethanol has a high octane, why are the octanes across the country being reduced? I would think it help ought to raise or at least maintain the rating of any given gasoline.
The politicians are making token attempts at trying to fix problems.
One positive thing, at least ethanol is made in this country that is unless our farmers are moving to China also. Gasoline has been crap ever since the lead came out. That being said, I do not want lead back in it.

 

Mike,
I'd like you to elaborate on how an OX sensor shifts it's switch point from the "designed point for undiluted gas" to that for an addition of alky that cause the stoich to shift?.... maybe the design has been already been shifted to meet the Ethonal mandate!

The Indy cars do indeed run alky and have for a long time as we do here in our local racing.
Among the reasons it is done are;
1. Keeping everyone legal to the same fuel with no additives.
2. Less fire hazard.
3. About a 10% power gain.
4. Octane rating is higher allowing large turbo boost pressures.
5. Engine cooling ease.
The gain in power is a bit complex to understand but boils down to the cooling effect alky has on the intake air causing density increase is the major reason for the power gain results. Ethonal dos'nt do as well from this stand point.
To gain from alky, in broad terms, the compression needs to be raised as well to get back the power loss from the low BTU content, increasing the power conversion efficiency on the power stroke.
Just having high octane fuel by it'self does not make power unless other things are done to compliment it's use.
The only thing that can make use of the extra octane in a motor that has been designed for 87 octane is advancing the ignition timing to make up for the slower combustion rate of the fuel and gain some torque.
The peak cylinder pressures still have to occurr within same narrow limits after top dead center on the power stroke.