91 Octane vs 93?

[evin23]

hi have a manual eco boost 2015 mustang. live in west texas near the border and only see 91 octane premium fuel. was wondering have much power and torque I lose will running 91

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[dragonacc]

Seriously man, I know you are new but search the forum. You won't make a bunch of friends asking the same question that's been asked multiple times.

 

[odspice14]

Ive been wondering the same thing. I haven't searched but Ive been checking this site out for about a year or so and I don't recall seeing anything that jumped out as far as previous posts discussing 91 vs 93 octane gas. Then again Im only going to spend my time on threads that seem of interest to me. My time is too valuable to go on a hunt for something buried. Why so Serious? its only a discussion forum. You can not honestly tell me in the course of your life that with family or friends you have never ever had a conversation that basically is the same topic and discussion more than once.

 

[dragonacc]

Ive been wondering the same thing. I haven't searched but Ive been checking this site out for about a year or so and I don't recall seeing anything that jumped out as far as previous posts discussing 91 vs 93 octane gas. Then again Im only going to spend my time on threads that seem of interest to me. My time is too valuable to go on a hunt for something buried. Why so Serious? its only a discussion forum. You can not honestly tell me in the course of your life that with family or friends you have never ever had a conversation that basically is the same topic and discussion more than once.

Sure, but my life doesn't have a search button. This forum does.

 

[greg hazlett]

In talking with Adam from MAP 10-15 hp is what he thinks 91 vs 93 is worth with a tune.

 

[odspice14]

Sure, but my life doesn't have a search button. This forum does.

So now message boards are only good to use as a search engine? I guess give us both a ticket as you seem to be here to protect and serve as part of the message board police department.

 

[dragonacc]

So now message boards are only good to use as a search engine? I guess give us both a ticket as you seem to be here to protect and serve as part of the message board police department.

If you want to be lazy and not even try to find the answer go ahead and make a new thread. If you try and fail that's a completely different story. I'm not the only one that finds it annoying, I'm just the one that said something this time.

And I would absolutely make people use the search function if I was a moderator on this board. :tsk:

 

[GoBlues38]

zero!

On a normally aspirated car, you will see zero performance gain running 91 vs 93 octane.

 

[greg hazlett]

zero!

On a normally aspirated car, you will see zero performance gain running 91 vs 93 octane.

Except this is not a natural aspirated car, it happens to be forced induction...

 

[BGolden]

The gas quality in Oklahoma is very poor worse than Texas' 91. You will loose about 2 degrees of timing from what I have seen and can cost close to 20 hp.

Hope this helps.

Brad

 

[GoBlues38]

Except this is not a natural aspirated car, it happens to be forced induction...

Sorry. i did not see that he was running an eco boost.

91 would not be ideal, but it won't hurt the car. It is still possible you will get full horsepower from 91, even 87.

the car does not always pull timing just because of the lower octane. It senses the predetination (knock) and then pulls timing which lowers power. Higher octane fuel is more resistant to the conditions that cause predetination.

Thats a long winded way to say it is hard to put a number on lost power without logging what the computer is doing.

 

[greg hazlett]

That contradicts what Ford says, the say to get the full 310/320 out of it prem fuel is required.

 

[Herr_Poopschitz]

This whole thread...:tsk:

Rule #1. Search

#2. Pay attention to what you're reading.

#3. Know wtf you're talking about before responding.

#4. If in doubt, don't reply. Sit back, shut your figurative pie hole and focus on #2. God forbid you might learn something.

 

[GoBlues38]

That contradicts what Ford says, the say to get the full 310/320 out of it prem fuel is required.

Higher octane doesn’t necessarily mean more power. It will, however, give you a larger margin of error against detonation. Only you can be the judge as to what’s best for you, but if you choose to run the cheap stuff keep a keen ear out for the nasty clacking sound—detonation.

 

[BGolden]

I had a stage 1 Rousch ecoboost on the dyno a few days ago and the customer did not know to run 91 in it. He put 87 oct in it and it put down 215 hp. I'll find the graph and post it tomorrow.

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