So I tried 89oct to save a buck...whoops.

[Mr_Q]

Man...I thought I'd save $0.12 a gallon and switch to 89 octane.
On the highway this morning around 4200-5000rpm I was pinging like mad!
I've always run 91(Chevron). Guess I will stay that way!

Never pinged before and I did a complete tune-up only 3 months ago.

 

[~Stangzorized~]

If your sig is correct then I see no reason why you are pinging with 87 octane. The only performance mod you have is mufflers lol.

It's not the octane, it's your car. :canflag:

 

[Beau]

if you are still running on a stock tune then look at your owners manual, it says that 87 is the recommended gas

 

[DerekStangGT]

please describe this "ping"

 

[mrvax]

Some GT's do ping even in stock form. (Mine did not.) The timing may be "off" on the car or something. I remember Bierbelly's car pinged from day 1, even before his headswap.

It's good you tried the 89. If you don't ping then you don't need the higher octane.

 

[FallenPhoenix]

Would a dealer do anything about pinging with recommended fuel?

 

[Sam98]

If your sig is correct then I see no reason why you are pinging with 87 octane. The only performance mod you have is mufflers lol.

It's not the octane, it's your car. :canflag:

That is a ludicrous assertion. There are many factors that affect octane requirements and most of them have nothing to do with the car. That is why the owner's manual says that if the car pings use a higher octane gas. I would certainly agree that it COULD be his car, but that is certainly not the only explanation for his problem...

 

[forpit2000gt]

my car pinged with 87 from day one. now I have to run 93 with the T/A.

 

[Mr_Q]

Well I doubt it's the car. This is the first it's EVER pinged. And it's doing it with the first tank of 89 I have ever put in it. I always run 91 in my cars.

If you do the research....by the time the fuel reaches the combustion chamber...due to a number of factors...the octane rating is much lower than it was when you first put it in your tank. 91 can get as low as 85 at ignition!

You learn all of this when you deal with turbo cars. As I did for quite a while with my old Thunderbird Turbocoupe. [gawd I miss that car]

Higher octane gas will almost never do your [modern] engine bad. Then again, it may not benefit it either. So, yes, the cars are designed to run with 87. But 91 can yield a cleaner burn allowing for a more efficient combustion. Plus 91 fuels can contain less particulate matter thus your fuel filter will last longer.

In my case my car has adapted to 91 octane, obviously. Anything lower it pings. It could mean something else is wrong though. So much so that I ping with anything less than 91. I will look in to that.

 

[2000GTnoExtras]

That is a ludicrous assertion. There are many factors that affect octane requirements and most of them have nothing to do with the car. That is why the owner's manual says that if the car pings use a higher octane gas. I would certainly agree that it COULD be his car, but that is certainly not the only explanation for his problem...

Actually my owner's manual says (I can get the exact wording later if it's a big deal) if it doesn't run correctly on 87 take it to the dealer.

A service writer at Ford told me any gas is fine in it. I always run 87.

 

[jadesville]

Well I doubt it's the car. This is the first it's EVER pinged. And it's doing it with the first tank of 89 I have ever put in it. I always run 91 in my cars.

If you do the research....by the time the fuel reaches the combustion chamber...due to a number of factors...the octane rating is much lower than it was when you first put it in your tank. 91 can get as low as 85 at ignition!

You learn all of this when you deal with turbo cars. As I did for quite a while with my old Thunderbird Turbocoupe. [gawd I miss that car]

Higher octane gas will almost never do your [modern] engine bad. Then again, it may not benefit it either. So, yes, the cars are designed to run with 87. But 91 can yield a cleaner burn allowing for a more efficient combustion. Plus 91 fuels can contain less particulate matter thus your fuel filter will last longer.

In my case my car has adapted to 91 octane, obviously. Anything lower it pings. It could mean something else is wrong though. So much so that I ping with anything less than 91. I will look in to that.

good info

 

[Turbo92PGT]

I noticed that if i gun it hard in second or higher, around 2k - 2500 rpm mine will ping. I run 87. Any way to adjust the timing on the distributorless ignition?

 

[Sam98]

I noticed that if i gun it hard in second or higher, around 2k - 2500 rpm mine will ping. I run 87. Any way to adjust the timing on the distributorless ignition?

Timing adjuster, chip, or change the PCM timing tables...