What Octane gas does everyone run?

[Jekyl]

I run Premium 91 Octane. My car seems to respond better to it than it does 87 Octane.

What all do you guys run and do you notice a difference? I find it only costs about 5 dollars more per tank to fill up with 91 instead of 87. That means I just have to eat McDonalds 4 times instead of 5 times a week.

 

[super302]

I've used 93 octane and now i use 89, no real difference in power....i'll continue to use 89 to save up some $$$

 

[Daggar]

If you're not knocking and pinging with teh 87 gas then you're throwing that extra Big Mac away for nothing. hehe

I run 91 Octane and am running 8 lbs of boost from a Kenne Bell. Prior to the install, I ran the 89 or 87 (so long as it wasn't a ethanol/methanol mix).

*Slightly off topic*
Some gas stations out there are getting shady about those ethanol mixes by the way. You boosted guys be careful! By law, they're supposed to identify it. Some don't while other have a little sign at the pump the size of a postage stamp telling you about it. One station near here was closed down recently because they caught them cutting half an half inside of the tank with the normal mix and the ethanol mix (which is two counts of illegal activity).
They sell you crappy gas and charge full price!

 

[green]

i run 93

 

[Hissing Cobra]

I run 93 octane as well. I've got too much money invested in this beast to be risking detonation. If ya want reliability and longevity, it's the only way to go. But if your car runs on 87, 89, or 91 without issues, you'll be fine.

 

[2000 blown conv]

I run Premium 91 Octane. My car seems to respond better to it than it does 87 Octane.

What all do you guys run and do you notice a difference? I find it only costs about 5 dollars more per tank to fill up with 91 instead of 87. That means I just have to eat McDonalds 4 times instead of 5 times a week.

Sunoco gold 94 octane..

 

[Jekyl]

I found my car runs noticebly better on 91 than 87. Not many gas stations around here have 93 octane. I think I will stick with 91.

Quick question, I was told to use octane booster when I go to the track, is it worth it to pay 13 bucks for a can of Octane booster? Is there any real performance gain or is it just a waste?

 

[HISSIN50]

some folks have noticed that they run better on 91 than 87, even when stock. i run 87 and it seems fine for me (15* timing in winter, 10 in summer. it is 109*F today!).

if someone is searching or reading about 94-95's, because of the horrible factory fuel and timing tables, 91+ octane is almost a must.

 

[Hissing Cobra]

Octane booster is for people who are running on the edge of detonation, either by advancing the timing or running with too high of a compression ratio. A lot of people will advance the timing to pick up a little power, but this comes with the problem of detonation. Octane boost will allow you to advance the timing a bit more and provide more octane to prevent detonation. If your car runs fine on 91 or whatever, you'll be fine with that.

 

[Stang8URMPRT]

My car's always had 93 in it, from the day it came home from the Ford dealer, till today. Timing is also advanced. If 87 or 89 is put into the car, it hesitates and the exhaust pops.

 

[srothfuss]

The higher octane is harder to burn (hence reducing detonation) so if the car isn't pinging or knocking when it's under load then I woudn't switch.

 

[88_GT_5_oh]

i run 91..... for the extra $5 i'll take the little extra insurance.

sad part is i just paid $40 for 40 liters of gas (in canada its sold by the liter)
so bassically it cost me $3.81 for a gallon ($3.02 US dollars a gallon for gas)

 

[Loco5.0]

This should be in 5.0 talk not tech.

I run 93

 

[89MustangGX]

I use 87 all the time in my F150, I've been running it in my Mustang as well, butthinkingabout trying more octane to see how it runs.

 

[Deleted member 87397]

The higher the compression of the engine the higher the octane you need. A stock stang should run fine on 87 or 89, but when you start bumping up compression with pistons, heads, and boost, or if you have super advanced timing then you need higher octane. However, even lower compression cars should respond a little better to higher octane fuel. Also, your altitude above sea level plays a role in what grade you can use and still be okay. An engine doesn't need as high of an octane rating at higher altitudes. That's why it's harder to find anything above 89 or 91 at higher elevations. I'm running stock heads on my 86 with a ton of bolt-ons and a chip so it runs much better on 93 than lower grades, but before I started modding It ran fine on lower grades. I have an IS300 for my daily driver the compression ratio on it is 10:1 so it runs like complete ***** if I use anything less than 93.

 

[gaslight]

93 here. No problems with 10psi

 

[HISSIN50]

This should be in 5.0 talk not tech.

I run 93

Compared to some of the threads in here, this is just fine IMHO (I think it is tech on its own merit).

 

[stang22]

93... Plus a 453 octane booster, making it around 546 octane. That gives me about 43.7 extra horse power. 44 extra HP if it is below 72.49 degrees outside... give or take a few hundreths.

The above statements make this thread officially "Tech".

 

[HISSIN50]

also if not mentioned, running higher than needed octane actually can lower performance and increase emissions.

The octane used and timing both go hand in hand (as well as static tangibles like FastFox mentioned).

 

[Daggar]

also if not mentioned, running higher than needed octane actually can lower performance and increase emissions.

The octane used and timing both go hand in hand (as well as static tangibles like FastFox mentioned).

I was going to say something but it seemed that everyone was on the "higher is better" bandwagon. Running higher octane than what is required by your car is throwing HP out the window. Lower octane gas has lower flash point (ignites more easily) and burns hotter. Advancing timing to the point where higher octane is required (with no other mods) is an exercise in futility. Running a lower octane gas and less timing will usually net you better HP than running advanced timing and higher octane gas.

Forced induction is a slightly different matter but for the most part, the same applies. However, the higher octane gas used with forced induction that allows you to run at least base timing for a given engine is ideal. Even then though, increasing ONLY the timing in a forced inducted application too much past base making it necessary to run an even higher octane will normally net you a loss vs. running base and a slightly less octane.