Compression question

[OldPhart]

I’m new to Mustangs. Just a curiosity question. With the 12:1 compression ratio on these new engines, is 93 octane high enough? I assume everybody uses 93 octane for routine driving. Does the computer automatically adjust to whatever octane fuel we use? I’m not a gear head so excuse the naive question. I’m used to muscle cars from the ‘60s and without adjusting the timing my GTO (10.5:1) detonates on anything less than 93 octane and adjusting the timing isn’t the ideal way to get rid of detonation. I could use some educating on this issue... Bruce

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[EFI]

Yes 93 is enough. And yes, the computer manages timing very well and can even be run on lower octane gas.

Check your manual for recommended and minimum octane.

Ford would not make a mass produced car that could not be run on the gasoline available in 99.9999% of US gas stations if the engine would not work on 93.

 

[LETHAL]

12:1 is far different with duel injection of today vs. 12:1 of the 60's-70's.

That said, can you run 87-89 octane..yes Would I? No.

It's worth every penny extra to me to get every horse power available.

That and I can't anyways, mine is tuned LOL

 

[OldPhart]

12:1 is far different with duel injection of today vs. 12:1 of the 60's-70's.

That said, can you run 87-89 octane..yes Would I? No.

It's worth every penny extra to me to get every horse power available.

That and I can't anyways, mine is tuned LOL

Thanks. At my age I won’t be doing any tuning, etc. that will require extra octane. That could be dangerous to my health... Bruce

 

[NoVaGT]

Thanks. At my age I won’t be doing any tuning, etc. that will require extra octane. That could be dangerous to my health... Bruce

No.......tuning doesn't "require extra octane". You can run 93 octane, or you can get a tune to run lower octanes, although I don't know why you would.

And I'm baffled by "That could be dangerous to my health..."

 

[Livernois Motorsports]

It is Idea to run the higher octane fuel because it will burn cleaner. Will get you better mpg and also the most power. If you start doing dedicated performance tunes to it then you would have to run that octane only. But the manual I'm pretty sure says you should not run anything less then 91 octane.

 

[OldPhart]

No.......tuning doesn't "require extra octane". You can run 93 octane, or you can get a tune to run lower octanes, although I don't know why you would.

And I'm baffled by "That could be dangerous to my health..."

At my age, 77 in January, anything that results in a faster car is potentially dangerous. I say this as self deprecating or tongue in cheek humor. I’m old so I can poke fun at my old age... Bruce

 

[OldPhart]

It is Idea to run the higher octane fuel because it will burn cleaner. Will get you better mpg and also the most power. If you start doing dedicated performance tunes to it then you would have to run that octane only. But the manual I'm pretty sure says you should not run anything less then 91 octane.

Thanks, I’ve been getting a good education on octane, tuning and engine compression. I had a ‘91 LT1 Corvette so I am superficially aware of these issues but weak in the technical reasoning area... Bruce

 

[brucelinc]

At the drag strip where I run there is a 78 year old who runs his 1971 Chevelle. His reaction times may not be quite what they once were but he has a lot of fun and is great to chat with. His little brother is only 75 and they are always together at the track. It is great to see older folks still messing around with fast cars.

 

[OldPhart]

At the drag strip where I run there is a 78 year old who runs his 1971 Chevelle. His reaction times may not be quite what they once were but he has a lot of fun and is great to chat with. His little brother is only 75 and they are always together at the track. It is great to see older folks still messing around with fast cars.

Hey, thank for the compliment. I graduated from H.S. In 1960 and was fortunate to experience the ‘60s muscle car era. We’re all fortunate that it has been resurrected and I can state that once it’s in your blood it stays. As you can see from my profile I also have a ‘65 GTO, a sibling to the one I bought new upon graduating from college. Like so many, I went through the family era with Buick’s, Hondas, etc. My mid-life crisis car was a ‘92 Vette which reminded me of the fun I had been missing for so many years - never again until they hide my keys on me... Bruce

 

[brucelinc]

Hey, thank for the compliment. I graduated from H.S. In 1960 and was fortunate to experience the ‘60s muscle car era. We’re all fortunate that it has been resurrected and I can state that once it’s in your blood it stays. As you can see from my profile I also have a ‘65 GTO, a sibling to the one I bought new upon graduating from college. Like so many, I went through the family era with Buick’s, Hondas, etc. My mid-life crisis car was a ‘92 Vette which reminded me of the fun I had been missing for so many years - never again until they hide my keys on me... Bruce

Glad you are on the forum, Bruce!

 

[Zinc03svt]

4 knock sensors on 18 plus cars help keep things alive. Fun to see this muscle car revival for sure.

 

[Blue Horse]

Glad you are on the forum, Bruce!

I graduated from High School in 1964,and I remember the fond old days,now at 73 years old, my 2011 Mustang GT put's a smile on my face everytime I press on the right side pedal !!

 

[OldPhart]

I graduated from High School in 1964,and I remember the fond old days,now at 73 years old, my 2011 Mustang GT put's a smile on my face everytime I press on the right side pedal !!

Thanks... Bruce

 

[2018OFPP1?2]

I’m new to Mustangs. Just a curiosity question. With the 12:1 compression ratio on these new engines, is 93 octane high enough? I assume everybody uses 93 octane for routine driving. Does the computer automatically adjust to whatever octane fuel we use? I’m not a gear head so excuse the naive question. I’m used to muscle cars from the ‘60s and without adjusting the timing my GTO (10.5:1) detonates on anything less than 93 octane and adjusting the timing isn’t the ideal way to get rid of detonation. I could use some educating on this issue... Bruce

Your unmodded 2018 mustang will run just fine on 87 octane fuel, it just won't achieve full potential horsepower.

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