What octane - TToTD

[BLACK-MACHINE]

my owners manual says 87 octane. i've read and see on the forum that everyone is running 93 or better. car is an 09-GT.

 

[weather man]

my owners manual says 87 octane. i've read and see on the forum that everyone is running 93 or better. car is an 09-GT.

If you are running stock with no tune, 87 is fine. The reason guys are running 93 is that they have been tuned to take advantage of the extra octane.

The search button here is your friend. You can get roasted on here for questions like this. Put your due diligence in .

 

[S197gt07]

What did I tell you man? Jeesh! (EDIT: looks like I was 7 min late)

2nd day on the side and TToTD

 

[fdjizm]

Fill 'er up with diesal!

 

[Deez-67]

<--91 daily tune

 

[Captainstr8edge]

Get a tune, THEN run 93, otherwise it will do nothing for you.

 

[stkjock]

apparently you did not read what was posted here:

http://www.s197forum.com/forum/showpost.php?p=1817089&postcount=3

 

[BLACK-MACHINE]

wow you guys are tough,,, i be more careful in future post

 

[dark steed]

For what it is worth, I ran both grades before my CAI and tune. No dyno test besides the "butt dyno" but it felt stronger with 93. I also got better fuel mileage, enough to offset the difference in cost..

Also, welcome to tech roast! Lol
Stick around, a wealth of info and good guys on here!

 

[Captainstr8edge]

For what it is worth, I ran both grades before my CAI and tune. No dyno test besides the "butt dyno" but it felt stronger with 93. I also got better fuel mileage, enough to offset the difference in cost..

Also, welcome to tech roast! Lol
Stick around, a wealth of info and good guys on here!

http://kalecoauto.com/index.php?main_page=product_info&cPath=6&products_id=8 only $529.95!!

 

[VTXFrank]

wow you guys are tough,,, i be more careful in future post

Never post in Tech unless you're turning wrenches, taking shit apart and/or putting shit back together.

For what it is worth, I ran both grades before my CAI and tune. No dyno test besides the "butt dyno" but it felt stronger with 93. I also got better fuel mileage, enough to offset the difference in cost..

Also, welcome to tech roast! Lol
Stick around, a wealth of info and good guys on here!

Dark Steed, your butt-dyno is fucked. Don't ever depend on it again. And buy yourself a calculator.

In a car that hasn't been tuned for 93 octane, 93 octane will result in less power and less mileage.

I can't believe that with the Internet being so inclusive, people still have this idea that higher octane = more power. Higher octane burns slower than 87. You get the power by adjusting your timing to take advantage of this. The more timing you throw at an engine, the more power. The trade off is you also risk detonation. Higher octane gas simply lowers the chance of detonation. Nothing more.

http://kalecoauto.com/index.php?main_page=product_info&cPath=6&products_id=8 only $529.95!!

 

[Deez-67]

Dark Steed, your butt-dyno is fucked. Don't ever depend on it again. And buy yourself a calculator.

In a car that hasn't been tuned for 93 octane, 93 octane will result in less power and less mileage.

I can't believe that with the Internet being so inclusive, people still have this idea that higher octane = more power. Higher octane burns slower than 87. You get the power by adjusting your timing to take advantage of this. The more timing you throw at an engine, the more power. The trade off is you also risk detonation. Higher octane gas simply lowers the chance of detonation. Nothing more.

^^ Truth!

 

[BLACK-MACHINE]

so ask about shifters and stuff here, but post the actual replacement in tech

 

[stkjock]

so ask about shifters and stuff here, but post the actual replacement in tech

opinions on what to buy = chit chat

how to install question = tech

 

[dee99gt]

tune it and then run 93... I run 93 after my tune.

 

[BruceH]

What Frank said is so true.

OP your stock tune will go to a max of 26 degrees of spark advance. I'd be about 99% sure your spark is advancing to at least 25 if not 26 on e10 87 octane. There is no more room left in the stock tune for any benefit from more octane. Stock 4.6 3v motors that are tuned for premium usually go about 31-33 degrees although I did see a "big name" canned tune only go 27 at a dyno day. I was able to run 32 with 11:1 compression and 92 octane.

Stick around. The more you read on this site the more you will "invest" in your car, lol. We all enable each other to do more to our cars by posting what we do and reading about what everyone else is doing.

 

[BLACK-MACHINE]

LET me try and clear things up a bit.. before i even bought the car many told me that it required 93 octane.
i understand when you have a turbo or SC or a programer you need to run 93 ( wifes car is SC from the factory ).
so at 1AM in the morning on the shake down run i need gas real bad ( 2 miles to empty) so i stopped flipped open the fuel looked at the gas cap and noticed it read ford recommends BP fuel and not to use E-85.so i jump back in the car rip open the manual , and find fuel rating says 87 or better, so not wanting to mess things up and knowing i can get gas 12 miles down the road i buy 1 gallon of gas,, yeah just 1 gallon, i pulled out, headed on my way listing for the dreaded knock and ping , car ran fine so i filled her up with 87. i hope this clears things up a bit... thanks for understanding..

 

[skwerl]

Oh, don't run your car down that close to empty. You will burn up the fuel pump, it is cooled by the fuel and will overheat if you constantly run your car that close to empty. When the dash buzzer goes off at 50 miles to empty, stop and put gas in it.

 

[dark steed]

Dark Steed, your butt-dyno is fucked. Don't ever depend on it again. And buy yourself a calculator.

In a car that hasn't been tuned for 93 octane, 93 octane will result in less power and less mileage.

I can't believe that with the Internet being so inclusive, people still have this idea that higher octane = more power. Higher octane burns slower than 87. You get the power by adjusting your timing to take advantage of this. The more timing you throw at an engine, the more power. The trade off is you also risk detonation. Higher octane gas simply lowers the chance of detonation. Nothing more.

For what it is worth, I DO have a calculator. All mileage was OBSERVED mileage, since I calculate almost every tank this way. It was also over several tanks with various mixes of highway/city driving. I'll take my empirical calculations and observations over your internet information any day. Like I said, the performance may have been imagined, but the mileage was cold, hard numbers.

I got just over 1.6 MPG better (average) and 93 is $.30/gallon more. Assuming a 15 gallon fill up, it broke even when 93 was over $4/gallon, Not so much when it came down to $3.50/gallon. The mileage was the only way to justify the added cost of the 93...I have a CAI now so it is a moot point; there is no denying that it runs better on 93 now! LOL

I also had a '98 Explorer 4.0 SOHC and tried both grades. It ran worse and got worse mileage with the 93, which supports your position.

One does have to wonder; however, since the mileage improved, perhaps the engine DID run better?

 

[BruceH]

For what it is worth, I DO have a calculator. All mileage was OBSERVED mileage, since I calculate almost every tank this way. It was also over several tanks with various mixes of highway/city driving. I'll take my empirical calculations and observations over your internet information any day. Like I said, the performance may have been imagined, but the mileage was cold, hard numbers.

I got just over 1.6 MPG better (average) and 93 is $.30/gallon more. Assuming a 15 gallon fill up, it broke even when 93 was over $4/gallon, Not so much when it came down to $3.50/gallon. The mileage was the only way to justify the added cost of the 93...I have a CAI now so it is a moot point; there is no denying that it runs better on 93 now! LOL

I also had a '98 Explorer 4.0 SOHC and tried both grades. It ran worse and got worse mileage with the 93, which supports your position.

One does have to wonder; however, since the mileage improved, perhaps the engine DID run better?

Maybe it was a difference in gas station pumps and level of vehicle? 1.6 is significant. What year and motor?