regular or premium???

[oh9mustang]

5 0
I'm not getting any more hung up than you are. Slower doesn't mean velocity when we are talking burn rate, but it does mean slower when you say that a fuel will burn longer and somehow not burn slower. That’s just not possible. I'm not real sure just why you can not understand that slower and longer are the same when talking fuel burn with a given amount of fuel. I'm beginning to think your just arguing to be arguing, 2 and 2 does equal 4 don't it?
Again, What chuck asked was is how much better is premium for the car, I explained that premium is not better and would make a regular tuned car run worse. You have some math for outer space that goes against physics and tried to convince me and I'm guessing others that somehow a Fuel that will burn longer is not burning slower, that is just amazing.

 

[Five Oh Brian]

oh 9, tell you what, I really don't care to argue anymore, so let's just agree to disagree.

In summary, then: If anyone is going to burn premium fuel, please tune accordingly. And, for those tuned for premium, don't run regular. Can we just leave it at that?

 

[oh9mustang]

Yes

 

[mustangdave]

oh9, not that it matters AT ALL, but out of curiosity: do you mean that if the exact same amount of 87 octane and 93 octane burn at the same rate, the 93 will burn longer due to the chemical characteristics of the 93? It makes sense, just wanted clarification. I've always heard "slower" too, but what you are saying makes sense and I'm a curious critter. Hope this doesn't restart the bickering; I just like to learn.

 

[oh9mustang]

Dave
It is never wrong to ask questions. and along with that, The answers should make since. When you advance the timing on a engine the spark happens before Top dead center or TDC. Now a 83 octane fuel will ignite easier or sooner or faster depending on whatever math you wish to choose. The 93 octane will ignite slower or longer or later which ever math you choose. What does this mean to a 87 octane tune engine.
The Ford engineers have developed a tune that the 4.6 will run on 87 octane with the timing set at a retarded position. When adding a 93 octane fuel to a 87 octane tune the fuel will burn slower, that means less of the fuel will be burned and make that engine run worse.
Just why would Ford put a 87 octane fuel in a 87 octane tuned vehicle, because the rate of burn is what is required for this application. Ford engineers didn't got to school for years and years just to guess on what fuel to put in your car.
The reason a 93 octane fuel is put into a 93 octane tuned vehicle is because of the timing. the timing is advanced in a 93 tune and that makes the spark happen sooner. if the spark happens sooner you really don't want a fuel that will burn fast because the combustion will happen before top dead center and give the distinctive ping.
I you have a specific question I will be happy to give an opinion of clarify with justifiable facts.


I forgot to answer your question. Sorry, The answer would be YES.

 

[rd]

Somewhere I thought I had read that the puter could sense the fuel available and adjust timing to use the octane available.

I use 93 most of the time, because I do exercise the ponies frequently, and because my 4.6 truck refuses to tow with anything but. Apparently it does not retard the timing due to load and octane.

School me if there is a better way.

 

[40th GT]

Somewhere I thought I had read that the puter could sense the fuel available and adjust timing to use the octane available.

Apparently it does not retard the timing due to load and octane.

School me if there is a better way.

You are right. The 4.6 3V engines don't have knock sensors. So if you hear knocking, increase the octane.
Otherwise, stick with the lowest octane possible for these engines as long as there is no timing advance or forced induction.

 

[Five Oh Brian]

Somewhere I thought I had read that the puter could sense the fuel available and adjust timing to use the octane available.

The 2008-9 Mustang Bullitt was Ford's first 4.6L that had dual octane strategy (two different tunes based on the octane it senses). This same feature was incorporated into the all 2010 Mustang GT's. Earlier GT's did not have this feature. So, '10 Mustang GT owners can use whatever octane rating they want and the computer will figure out the spark/fuel tables automatically.

 

[Five Oh Brian]

The 4.6 3V engines don't have knock sensors. So if you hear knocking, increase the octane.

I'm curious. At our local dyno shop, we added some extra timing at higher rpm's in my '07 GT to see if we could safely pick up some power. However, during the pull, there was some detonation and the computer in my car automatically pulled timing way down (it was clear as day in the data logging). So, the tuner decided he should reduce total timing back down (I'm at 14 degrees now - which is all my non-cooled supercharger will tolerate with 92 octane fuel).

How did my '07 4.6L 3V know to pull timing if it doesn't have knock sensors?

 

[oh9mustang]

I believe they started putting knock sensors in mustangs in 1993, except for the 4 valve engines. I don't know why they wouldn't put them in the S197 like the 07.

 

[wusthof]

I get between 310-325 miles out of a tank.

do you skip shift every gear (manny), run on the hwy only and run er dwn all the way to empty. I'm definately not easy on my car on the weekend, but @ 4:45am on my way to work, I'm not into banging thru the gears either. anywhere over 415 kms to a tank, and I wouldn't believe it. I skip shift all the time, and run on the hwy on the way home. I live on a mountain too, but still..............

 

[40th GT]

I'm curious. At our local dyno shop, we added some extra timing at higher rpm's in my '07 GT to see if we could safely pick up some power. However, during the pull, there was some detonation and the computer in my car automatically pulled timing way down (it was clear as day in the data logging). So, the tuner decided he should reduce total timing back down (I'm at 14 degrees now - which is all my non-cooled supercharger will tolerate with 92 octane fuel).

How did my '07 4.6L 3V know to pull timing if it doesn't have knock sensors?

If I was wrong all you had to do was correct me. No need to be a smartass about it.

And oh9, my 04 GT sure didn't have knock sensors. I don't know why Ford did that either.

 

[Five Oh Brian]

If I was wrong all you had to do was correct me. No need to be a smartass about it.

40th, I'm really sorry if you thought I was being a smartass. I sincerely was not being a smartass (the hazard of the internet, where you can't hear voice inflections and read non-verbals). I really didn't know if our cars had knock sensors. I suspected they did, but did not know for sure - hence the reason I was asking for clarification from you. Again, sorry if you thought otherwise.

 

[40th GT]

40th, I'm really sorry if you thought I was being a smartass. I sincerely was not being a smartass (the hazard of the internet, where you can't hear voice inflections and read non-verbals). I really didn't know if our cars had knock sensors. I suspected they did, but did not know for sure - hence the reason I was asking for clarification from you. Again, sorry if you thought otherwise.

It's ok.

I really didn't know either. I was just going by my assumption that since my 04 4.6 didn't have it, the new 4.6s wouldn't either, save for the 4-valve 4.6.
With that said, I could have sworn I heard some marbles in a can while launching hard on a hot day with AC on. So I decided to use mid grade fuel until I have the chance to Seafoam the engine.

 

[Steel Horse]

do you skip shift every gear (manny), run on the hwy only and run er dwn all the way to empty. I'm definately not easy on my car on the weekend, but @ 4:45am on my way to work, I'm not into banging thru the gears either. anywhere over 415 kms to a tank, and I wouldn't believe it. I skip shift all the time, and run on the hwy on the way home. I live on a mountain too, but still..............

I take the back roads into work. The drive has a couple miles of city, and the rest is a mix between 35-55mph. I do skip gears in some areas (usually 3rd or 4th gear). I think the gradual grades where I drive and let the car coast helps me quite a bit. I almost always fill before the warning lights come on. I do an occasional blast up to highway speed, but it isn't an every day thing.

 

[Vulcan420]

Should I use high octane gas in my GT?

Its really quite simple:

According to the owners manual - You should not use high octane gas because it can cause damage to your engine. Maybe people should try reading their owner's manuals.

If you do an aftermarket tune on it then you will need to use high octane fuel.

See, its so simple you dont even need to know what octane rating means - just how to read.

 

[Five Oh Brian]

Should I use high octane gas in my GT?

Its really quite simple:

According to the owners manual - You should not use high octane gas because it can cause damage to your engine. Maybe people should try reading their owner's manuals.

If you do an aftermarket tune on it then you will need to use high octane fuel.

See, its so simple you dont even need to know what octane rating means - just how to read.

That's funny, my owner's manual (07 Mustang) does NOT say that high octane fuel will damage my engine, as you claim. Here's exactly what it says in my owner's manual....

Octane recommendations

Your vehicle is designed to use
“Regular” unleaded gasoline with
pump (R+M)/2 octane rating of 87.
We do not recommend the use of
gasolines labeled as “Regular” that
are sold with octane ratings of 86 or lower in high altitude areas.
Do not be concerned if your engine sometimes knocks lightly. However, if
it knocks heavily under most driving conditions while you are using fuel
with the recommended octane rating, see your authorized dealer to
prevent any engine damage.

And my 03 Mustang manual says that 87 octane "minimum" should be used - again, nothing said about a higher octane being bad. I also grabbed a 2010 Mustang manual and checked what it said for the V6 model (since the V8 now has a dual octane strategy, while the V6 doesn't) and it also says to use 87 octane "minimum" with no mention of a maximum octane to avoid damage.

 

[mustangdave]

My '08 manual also says that higher octane may cause engine damage.

 

[oh9mustang]

If your manual says use 87, then use 87, It doesn't have to tell you not to use something, It would have an endless list of things not to use. Your manual says use 5W20, It doesn't have to say don't use 20W50.

 

[Five Oh Brian]

If your manual says use 87, then use 87, It doesn't have to tell you not to use something, It would have an endless list of things not to use. Your manual says use 5W20, It doesn't have to say don't use 20W50.

But, I've now read a couple different years of Mustang owners manuals that say to use a "minimum of 87 octane" and not to use anything lower. "Minimum of..." implies that running something higher than said amount is okay.