Obviously, judging from the posts I've read here, there are those who run higher octane than 87 in their V10 without problems.

When I bought mine, a friend told me to be sure and only buy 87 or I would have problems. He said his 5.4 started running like crap after putting super in the tank, so he took it in. The guys (apparently) told him that the problem was because the octane rating was higher than Ford's recommendation. Another Ford truck owner with a 4.6 told me he had heard the same thing.

Naturally, I thought they both were full of it, so I checked the owner's manual which said (basically) the same thing that they had told me.

My truck would ping (sometimes) when it was in OD and I was driving too slow. It was very annoying, but I'd just get it to downshift and all would be well. I was tempted to run higher octane, but was afraid to based on what I'd heard and read.

So what gives? If running mid grade or super is OK, then why does Ford say to ONLY run 87?

 

Hey John, ive ran premium gas numerous times,many times, before i installed the tuner and never have had any problems ever.I think it is bs.

 

I had the pinging in overdrive occasionally too. I have always ran 87 octane in my V10. What seemed to help me was to disconnect my battery overnight, then re-connect it in the morning and let the computer re-learn the engine. I just got back from a 2000 mi. trip with many mountain passes and didn't get any pinging the whole trip. I've read where the computer will adjust to higher grades of gas, but to reset it to regular 87 octane you will need to do what I did above.

Hope it works.

 

I drive a 01 F250 SD, I run only 89 octane, I pull portable generators and or a 7200lbs trailer and still ahve no pinging. I got the truck with 10000 miles and since then have added another 28000, and this is the only gas I have ran.

 

Too high of octane will cause some fuel to go unburned and start causing buildup in the cylinders. Not everyone has problems with it, but running premium if you're engine isn't chipped or have a programmer that advances timing to take advantage of the premium, does absolutely no good and is just money down the drain. Most likely you will get worse mileage running premium as well. Stick to regular unleaded unless you're getting pinging.

 

Using premium when you only need 87 will also shorten the life of your catalytic converter.

Steve

 

Octane is and additive to SLOW down combustion!

STOCK Ford low compression engines do not need any fuel higher than 87 RON.

Chevron with Techron runs best for most Ford engine owners.

Running 89 or higher is just wasting money.

Running super will eventually foul the catilytic converter as noted above.

If you run a chip or in some other way have modified the base computer program to advance the ignition you may need to burn higher octane to prevent predetonation (pinging).

Higher octane than needed in a lowcompression motor yields less complete burn, slower burn and loss of power (very minute)

If you have a stock Ford motor that pings and is still in warrenty get it fixed!

Running mid grade when tow/hauling heavy loads helps prevent pinging that is induced by low rpm, heavy load, and increased engine/fuel temps.

There is no know mechanical engine problem that can be caused by running higher octane, except for fouling the cat and maybe increased carbon buildup on exhaust side.

On the other hand, if you feel the need to contribute more money from your wallet into Shell, Exxon, and the Federal Gvmnt please feel free to burn many tanks of $$ Super high test.... it helps the economy and keeps me employed!

 

Octane is not an addative it is the hydrocarbon itself, eight carbons chained together. Pentane has five, hexane has six, heptane has seven, Methane has just a single carbon atom. Propane has three carbon atoms chained together. Butane has four carbon atoms chained together.

It turns out that heptane handles compression very poorly. Compress it just a little and it ignites spontaneously. Octane handles compression very well -- you can compress it a lot and nothing happens. Eighty-seven-octane gasoline is gasoline that contains 87-percent octane and 13-percent heptane, now that is how it started but lead and other additives have changed the meaning and the term Octain has been used to mean reduces compression ignition.

I do agree with the rest of the post, nothing will happen by running high Octain fuel other than loss of money.

 

Also........the octane rating is just that...a statement that claims the gasoline will perform as if the octane was at 87%. With the additives and various formulations, the actual amount of octane may be different.

 

Thanks... I'm amazed how many informed people there are here; this is truly a great site.

So, other than being a waste of money, premium fuel will hurt nothing? Will it or will it not enable a complete burn, foul plugs, plug up my nonexistant catalytic converter, etc.?

Not that it will matter when I get the truck back on the road, but I'm curious.

 

It will hurt nothing!

 

Thanks, that was what I was looking for.

 

Sometimes in the midwest, at least in Iowa, there's a good reason to run 89 instead of 87 - it's cheaper. At all the gas stations around here, 89 octane is the ethanol blend and can be up to a nickel cheaper than 87, which doesn't have ethanol, so we usually run 89 in our van. When we're out of state and 87 is cheaper, we buy that. Haven't noticed any pinging under any circumstances in the 7 months/6000 miles we've had the van.

FWIW,
Isaac

 

Ok, some body correct me if I am wrong. If I run 92 all of the time and my ecu learns and adjusts timing for this, and I get pinging when I put 87 in, havn't I got the benifits of a chip or power programer? Why would I want to disco the batery cable and reset the computer??? Why would I want to retard the timing??

If I run down to a 1/4 tank of gas and fill up it takes about 20 gallons.
20 gallons of 87 at 2.29 is $45.80.
20 gallons of 92 at 2.49 is $49.80
$4 a tank, BFD!

By the way great info Damion!!

 

Your stock chip will only increase the timing by X amount, it will not increase it to the point of a chip, basicaly what a chip does is remove the safety limit. Remember the stock setting has to take into acount all grades of fuel a chip assumes super only.
As for changing, the knock sensor will retard the timing in milliseconds, you do not need to let it relearn. In fact there is no such thing as a learning computer, it will record you driving habits and them, then the computer will use that data to adjust shift points and as a starting point for fuel. The O2 sensor sniffs the exhaust gas and then will adjust timming and fuel from the base setting but it does it in again milliseconds. Timing is advanced till knock then retarded over and over again and a MAP is built so that the computer again has a base MAP but it is always adjusting. The only reason to ever reset the computer is if a limp mode was set or malfunction of some sort was flagged and you wanted to clear it. All the talk of reset the computer comes from people who do not understand the technology because a completly new map is written every driving cycle, the driving cycle is more often than not listed in the manuel.

68 the stock computer can not adjust the timing enough to take advantage of super unleaded so there is no reason to spend the 4 bucks unless you are just more comfortable doing it. There is less energy stored in super unleaded fuel than in regular, if you increase compression and timing you can utalize a higher percentage of the stored energy though, but do yourself a favor, run a few tanks of gas with regular unleaded then with super, if your driving is the same you will find you get better mpg with the reg. I get right at 1 mpg better on hwy driving.