Anyone have any comments about 87 vs 91 octane?

[v8thunder1]

I just wanted to know what people are running in their GT's. Pros/Cons?

 

[Satin Silver GT]

I run 87 in my 2002 GT with out any problems. Ford recommends 87 octane in the owners manual. Spoke with the Service Manager and he confirmed 87.

2002GT 5 spd
AutoMeter Lunar Gauge cluster
Hurst Billet Plus shifter
K&N
Magnaflow Cat back

 

[COBRA90GT]

Stick with the regular stuff unless you have advanced the timing and/or NEED the higher octane gasoline (ie. car pings with 87, but not with 89).

 

[DC-GT]

Stick with the regular stuff unless you have advanced the timing and/or NEED the higher octane gasoline (ie. car pings with 87, but not with 89).

Bulllseye!

Your mods will eventually cause you to need higher octane or a tune. I use premium once in a while just because it has more detergents in it to clean my valve train and injectors. I don't run it all the time because I don't want the detergents to mess with my injector seals.

Wow, that seemed confusing, lol.

Bo

 

[Beau]

for every 4 tanks of 87, i fill it with 1 tank of 91. i figure that as soon as i get any serious engine work done, i'll have to use 91 but until then i am going to save money

 

[downsouthman1]

I run 87 in my 2002 GT with out any problems. Ford recommends 87 octane in the owners manual. Spoke with the Service Manager and he confirmed 87.

2002GT 5 spd
AutoMeter Lunar Gauge cluster
Hurst Billet Plus shifter
K&N
Magnaflow Cat back

The manual does advise 87 oct. I did however, have a Superchip installed on my car. Before I had it done they told me I'd have to run 93 octane. I was in disbelief so I ran 87 the next time @ the pump after installation & my car bogged down to like 150 RPMs a lot. So during my next trip to the pump I ran 93 & have done so ever since & it's fine now.

 

[JonJon]

87.

 

['96&'01Stang]

I run 93 octane

 

[jimfitzgerald]

You should run 87 unless you have advanced timing or get pinging. Then you should up the octane. Running higher octane than you need will not give you more power, and may actually reduce power because it is more stable and harder to ignite.

 

[AdRock]

I ran 87, then 89, then 93. My car seems to like the 89 the best. It ran the same with 87 or 93 but feels like it has a little more pep with the 89.

 

[Jesus]

I too am running 89 in my car. I have a Steeda T/A set at 13* and tried 91, but the car didnt run as well as it does with 89. I havent been able to detect any pinging. I have tried to get it to ping by accelerating under load (going up hills in 5th) and havent heard a thing. Car just feels stronger with 89, and it doesnt hesitate off the line like it did with 91.

 

[19mustangGT97]

I dont get it, my 97 pings on 87 and 89 and sometimes pings at night on 91 with my cutouts open. Before I had my cutouts and only mods being flows and a filter it would ping pretty bad on 87 and 89. Don't know what my manual says but it seems it should be the same as 99+. Does anyone know why I ping on 87?

 

[jimfitzgerald]

I dont get it, my 97 pings on 87 and 89 and sometimes pings at night on 91 with my cutouts open. Before I had my cutouts and only mods being flows and a filter it would ping pretty bad on 87 and 89. Don't know what my manual says but it seems it should be the same as 99+. Does anyone know why I ping on 87?

Maybe the mixture is too lean or too much timing.

 

[19mustangGT97]

Yea but I have done nothing to my timing.. Everything was stock except the mufflers and filter and now the only thing new is the cutouts but I still ping on 87 with them open.

 

[2000GTnoExtras]

Yea but I have done nothing to my timing.. Everything was stock except the mufflers and filter and now the only thing new is the cutouts but I still ping on 87 with them open.

I would try replacing fuel filter, spark plugs (copper) and then resetting the ECU. You may wanna inspect your wires too.
Then fill it up with 87 and see what happens.

I put like $10.00 of 91 in my car every couple months, run 87 all the rest of the time.

 

[GreekStang85]

i usually choose 89 and every once in a while ill go with 93

 

[ASilver2001GT]

I run 93

 

[TripleBlk]

I just wanted to know what people are running in their GT's. Pros/Cons?

I run 87 now. When the car (99GT) was new, I was pinging out of the gate in tollbooths(I don't have to stop, I have one of those electronic passes), so I burned 93 octane until I learned the car wouldn't ping if I dropped it down into 3rd or second (duh). 87 works for me fultime now.

 

[NFCStang]

I seem to get better milage with 93 but I don't notice a power difference between that and 87-89

 

[340.29m/s]

I think everyone has pretty much said it, run 87 unless you begin to ping.

Cobras, Machs, and FI'd Mustangs on the other hand should run ATLEAST 91 octane (that is all we have around here)