Ecoboost Fuel Requirements 87 or 91+ octane?

[GMAN6]

Yeah, I see what you are saying, If it's not programed to run better on 91 or 93, then it won't.

It is flex fuel, so it is programed to compensate for different fuels, but whether it's programed to run better on 91 or 93, I don't know.

Regardless, it does get better gas mileage on 93 than 87.

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[DBCooper]

A higher octane fuel does not burn faster,slower, hotter, cleaner , or have more energy. All that a higher octane rating means is that the fuel can withstand more compression and/or advanced timing without pre-igniting. That's it, nothing more, nothing less.

That's why, if your car is tuned (compression and timing) to run on 87, it's a waste to run 92.

With new cars, they are designed to take advantage of higher octane by advancing the timing, but also retarding it (hence reducing power) if it senses lower octane (or pinging).

 

[Ziganrev]

I hope it'll run fine on 85 octane. 87 is the mid grade in Denver. 91 is the best you can get.

 

[EXP Jawa]

I hope it'll run fine on 85 octane. 87 is the mid grade in Denver. 91 is the best you can get.

My understanding is that the slightly lowered octane ratings in the mountain states is to account for the altitude, and corresponding lower oxygen content in the air. Perhaps someone else can explain it better.

 

[apexclipper]

Okay so -3 from what I said lol. That just means it will be even safer on 87.

Realisiticly with 9.5:1 compression on 91 you could probably run 25 psi and be fine, especially with DI.

"Run 25 psi" with 91 octane?

Where are you getting that information?

People are going to spend a lot of money on these cars, and they deserve solid, fact-based answers to their questions.

 

[JoeySD]

My VW GTI has a 2.0T FSI motor and I have always used premium gas...one time I used 87 and it ran poorly. On the gas cap door it says use premium fuel only !!! So yeah....

 

[apexclipper]

My VW GTI has a 2.0T FSI motor and I have always used premium gas...one time I used 87 and it ran poorly. On the gas cap door it says use premium fuel only !!! So yeah....

Same with my '10 and my present '13 GTIs...

But 91 is the minimum required octane requirement for the GTI.

The new Ecoboost is 87, with 91 or more being "recommended." The Ecoboost will run much better than our GTis on 87 octane, but it'll pull stronger and get better fuel economy with premium. The only fuel I'd run in the Ecoboost would be Shell V-Power (93 octane with lots of detergent). That's all I've ever run in my two GTis, and they love that gas.

 

[Swoope]

funny,

my 12 gti dsg. runs just fine on 87.. in fla usa.. and it is hot here.. difference if i am going to drive on track, i fill up with 93 on the way and while i am there.. so on a race track i get about 12.3 mpg.

on the way home i get about 1.5 mpg more than the way up...

about 29 mpg.


really, the ecu is a very smart thing..

beers

 

[JoeySD]

Very cool to see that many current GTI owners are very interested and excited about the Mustang EcoBoost !!!

 

[BugsOli]

Geez, I wonder what the difference would be here in Belgium where we only have 95 & 98 octane fuel!

If I go for the EB, I'll put it on the dyno with both to see the difference if any...

I know about the detonation and such, but with some mods wouldn't the higher octanes be better?

 

[SLVRBACK]

"Run 25 psi" with 91 octane?

Where are you getting that information?

People are going to spend a lot of money on these cars, and they deserve solid, fact-based answers to their questions.

With a good tune that psi to compression ratio relationship is realistic. I didnt say it was safe to do on the stock motor, nor do any of us know what the stock motor can withstand.

I was simply stating that that psi level is do-able and COULD be safe with that low of a compression ratio, especially with the cooling properties of Direct Injection.

 

[opensesame]

Yesterday after filling gas in my current car, I noticed Petro-Canada now supports 94 Octane Gas. Will I get more HP/Torque + MPG filling 94 Octane in the Ecoboost than 91/93, or should I just stick with 87?

 

[RoryTate]

The press release from Ford stated the 310hp/320tq numbers were from 93 octane. They didn't say what the numbers were for 87. Nor did they release MPG numbers for either.

There are a lot of other factors involved, such as the percentage of ethanol. In a nutshell: ethanol has less energy output per unit compared to pure gasoline. Mixing ethanol into gasoline will raise the octane rating, but lower the overall energy output.

http://pure-gas.org/ <=- see who in your area sells ethanol free gas.

 

[Suddueth13]

With a good tune that psi to compression ratio relationship is realistic. I didnt say it was safe to do on the stock motor, nor do any of us know what the stock motor can withstand.

I was simply stating that that psi level is do-able and COULD be safe with that low of a compression ratio, especially with the cooling properties of Direct Injection.

Actually that's not realistic because you're forgetting an important variable, turbo sizing. A KO3 turbo at 25psi flows a very different amount of airflow than a GT35 does at the same boost pressure. You could run 50psi all day on a super small turbo but that doesn't mean it will make power. 9.5:1 compression is fairly low by todays standards, even in boosted applications. Direct injection helps tremendously in keeping things safe, along with the advanced timing control. Adding water/meth injection would take the safety factor that much higher.

 

[geokots]

Here in Toronto the traffic is brutal during the week so peak power is useless. I takes me an hour each way in stop and go driving.

Does it make sense to use 87 for during the week work travel and 91-93 for weekend driving? I'm not sure if things adjust fast enough or if it'll take a tank to adjust to the higher octane.

I'll use what's needed but looking to save where it makes sense.

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