Is everyone running premium (92 octane minimum) fuel?

[praugue]

My 5.0s, '89 LX and the '92 GT, both have to run premium fuel. If any lesser grade is put in, I get pinging and rattling. I have no problem with this (it's not a friggin' Honda fer chrissake ), but I'm just curious why it needs the premium and if other Fox-body owners are doing the same.

I've done no mods, other than a K&N conical filter.

My mother drives a 4.6L '96 GT (I got a cool mom!), but she runs regular 87 octane or so with seemingly no problems.

 

[FrankenStang]

I run 92 in both my foxes. Both have advanced timing. Which is the only reason I use Premium.

I have a cool Mom too, she drives an '06 Stang.

 

[capri debris]

Check your timing... if you want to run 87 then you have to set it at factory 10*... if you are at 12* or 14* then you have to run a higher octane.

 

[25thmustang]

89 Octane

18 degrees of timing

Never heard the car ping once even with 20 degrees.

My Audi takes 91+, but I wont use that in the Mustang if I don't need it.

 

[FrankenStang]

89 Octane

18 degrees of timing

Never heard the car ping once even with 20 degrees.

My Audi takes 91+, but I wont use that in the Mustang if I don't need it.

 

[MustangOwner]

I ran 89 with 14 degrees timing, but it might make a difference that ALL gas in my state is atleast 15% ethanol. Soon i'll be running E85. That stuff is saweet.

 

[25thmustang]

No need for premium in it, why pay for premium. especially when they think people in the North East are all wealthy and can charge an arm and a leg for it. That and it runs alright with the 89, maybe I should toss some 87 in it, see if it runs better?

 

[ill advised]

87 in my '92 and 91 (our "premium" grade) in my '90.

 

[praugue]

Yeah, I have pushed the timing ahead a bit. I hand-tune until it runs the way I want it. It's probably about 15 degrees ahead or so. I'll have to check, but I do like the way they run on 92, and with advanced timing, much better.

 

[Disturbed90gt]

im running 92 and 110 mixed


and no all my mods arent listed. just havnt done it yet

 

[bloopbloob]

i'm running 87 with 16* timing now.

 

[FrankenStang]

Ummmmmmmmm, I really don't want to waste money on Premium if I don't have to.

 

[NIKwoaC]

89 Octane

18 degrees of timing

Never heard the car ping once even with 20 degrees.

My Audi takes 91+, but I wont use that in the Mustang if I don't need it.

I find that hard to believe. There are some schools of thought that anything over 18 is bad for a regularly driven car, even with premium (91+). tho, like someone said before, ethanol blends are common in fuels today, so maybe the fuel you use has some ethanol in it (effectively increasing the octane rating)? Do you regularly use additives like Sea Foam?

I'm not trying to call you out or anything, but 18-20 degrees seems like it could almost be counter-productive. Keep in mind the EEC-IV will compensate for some amount of knock by retarding the ignition.

Anyway, beautiful car man.

 

[RUNINAGT]

@ 1st I was running the highest, now I run the midgrade. Found no difference. Lightly modded though

 

[25thmustang]

I find that hard to believe. There are some schools of thought that anything over 18 is bad for a regularly driven car, even with premium (91+). tho, like someone said before, ethanol blends are common in fuels today, so maybe the fuel you use has some ethanol in it (effectively increasing the octane rating)? Do you regularly use additives like Sea Foam?

I'm not trying to call you out or anything, but 18-20 degrees seems like it could almost be counter-productive. Keep in mind the EEC-IV will compensate for some amount of knock by retarding the ignition.

Anyway, beautiful car man.

I understand, but this timing increase was done at the dyno, and the car made more and more power until I went for 20 degrees where it lost a little. Backed it to 18 and left it there. last time to the dyno it made no power differences from 14-18, so I left it on the last pull which was 18. There is zero additives ever put in it, and it has never made any pinging noise... Whether the EEC is doing anything is beyond me, thats where the car ran the best!

 

[skunk21]

I run 91 in the mustang due to the timing bump, although never tried 89 but I will now for the heck of it. the svt runs 91 per svt, you can run mid grade but the computer knocks down the power and the fuel mileage actually sucks.

 

[skunk21]

I understand, but this timing increase was done at the dyno, and the car made more and more power until I went for 20 degrees where it lost a little. Backed it to 18 and left it there. last time to the dyno it made no power differences from 14-18, so I left it on the last pull which was 18. There is zero additives ever put in it, and it has never made any pinging noise... Whether the EEC is doing anything is beyond me, thats where the car ran the best!

that's because you own a freak .

 

[25thmustang]

http://media.putfile.com/dyno-b-5
http://media.putfile.com/dyno-b-3

Dyno video... no pinging 18* and 89 octane...

6800 RPM on a stock motor?

 

[ryan218]

mines set at 10* i run 87 for now...

 

[85_SS_302_Coupe]

93 or better for me. Regardless of weather it's needed or not, it's cleaner burning and both my cars like it better (the Merkur actually has to have it with the boost).