The last time I filled up my EX (Tuesday 3-18-08) I put 93 octane it just because... I don't know I just did it.
Anyhow my first time ever with 93 octane in it, normally just the cheap haha 87 octane and my Lie-O-Meter is going nuts. It says I am getting 15.5 to 15.8 @58mph and 14.6 to 14.8 and around 68mph that's 2+ mpg then it normally says. Do you think octane makes the difference? I haven't dug out the owners manual yet to check but is it harmful to run 93 in the v10?
Thanks

 

Octane is an anti-knock factor and doesn't effect gas mileage. Generally speaking, high octane gasoline has fewer btu's than does lower octane gasoline and therefore, gets poorer mileage. Not sure what to make of the lie-o-meter.

There is nothing wrong with running 93 octane gasoline but it's a waste of money since it's not required for your engine.

 

Think of OCTANE is a measurement of the speef of the flame travel inside your cylinder. The SLOWER the flame travels thru the fuel/air mixture, the MORE time there is for the energy generated to be turned into mechanical energy, and the less wasted as heat.

The higher the compression, the higher the octane needed, because the more force that is applied to the fuel/air mixture, the faster it wants to ignite. When you get the compression too high for the flame-speed / octane of the fuel, you get "knock" or 'octane ping".

We arent going to get octane "ping" in our modern computer-controlled engines with "knock sensors", because they will retard or advance the spark as needed to get the most out of the fuel (in terms of spark advance) that the fuel will handle. But be ASSURED that you CAN NOT HURT your motor using any grade automotive fuel commonly avail. at legit. gas stations.

As a side-note, do NOT use aviation fuel. There is enough lead in aviation fuel to, over time, screw up your "smog muffler". That gets real expensive real fast.

I have NO idea what the compression ratio of our Ford V-10 motors is. But I do know that the truck's computer will advance the spark up to the point that it senses "ping".

As noted elsewhere, what you guys are calling a "Lie-o-Meter" is simply a fuel flow guage that "averages" fuel flow. In my own case ( a 2005 with less than 20,000 mi, I have found the fuel flow guage to be right on (when PROPERLY checking mileage "fuel FILL to fuel FILL").

Assuming you are using your fuel flow gauge and checking it correctly, and are actually showing that much improvement with higher octane fuel, it certainly seems like the spark advance profile in our V-10's is capable of advancing the spark far enough, and our motor's compression ratio is high enough, to take advantage of the "slower burning/higher octane" fuel.

What I do NOT know, is whether the additional cost of the "premium fuel" will get you sufficient performance / mileage gain to make it worth-while.

Next time I am going out with a heavy load in tow, I am going to have to try this out for myself !

 

I don't think using higher octane is going to increase mileage, just the amount spent at the pump......but, I wouldn't tow without super unleaded.

 

my X pings like crazy at low rpm (2000) when in a high gear..i drive like a granny and make the engine shift at around 2000..if going up a hill it will ping..after a downshift i dont hear it anymore..but it may still be pinging..i always use cheap gas..i have used higher octane in the past and i think it reduced the pinging.

 

Thanks for the Info
Basic math tells me that I think it is worth it, if the Lie o meter decides to start flying right and crank out the correct flow measurements, then I think it might be something to remember
Good Luck with your trial tank of high octane
Jeff

 

You arent using your head...T H I N K ! If higher octane gasoline stops the "ping"....T H I N K - what is your motor telling you ?

What do they teach in the basic high-school level CHEMISTRY and PHYSICS classes these days in high school ? Do they even HAVE courses in CHEMISTRY and PHYSICS in high school ?

I dont mean to pick on you personally, as others in this forum, and that I meet, have the same complete lack of understanding of the basics.

GET THAT THING TO A COMPETENT FORD DEALER ! It SHOULD be obvious to you that there isomething VERY wrong with your vehicle's "knock-sensor loop". You cant buy a low enough octane fuel today that would cause a modern vehicle to "ping" if the "knock sensor loop" is working.

Now that I have jumped all over you, thank you for your "post". SERIIOUSLY, you have helped me learn more about my V-10 ! What your "post" has told me, is what I SUSPECTED, but could not prove. Our V-10's DO have high enough compression to take advantage of premium fuels - your finding out that the use of premium fuel reduces the 'ping' confirms that !

The only question that we have not yet answered, is whether the improvement in effiency over-weighs the increase cost of premium fuel.

I wouldnt mind having more power on the long grades I tow our heavy boat - looking foward to seeing how this works out.

 

yea i understand..i know pinging is bad..and when i hear it of course i step on the gas so the engine shifts and it stops..i dont let it continue..ive read here that the v-10 has knock sensors and the like..like most vehicles, so i figured because of the cheap gas..the computer couldnt make it not ping..you are right..maybe there is a problem somewhere..everyone..does your v10 ping at all? if it does.....? you never hear pinging? and the way i drive...just a carryover from my job..truck driver of very fragile glass..and im a mellow fellow...everyone gets mad at me because i accelerate too slow from the light...the way i drive is a perfect setup for pinging..if i drive like most...like my wife...honestly i have never heard the engine ping when she is driving..she treats every stoplight like a dragrace..but that doesnt mean its not happening..good point you made 66....

 

I not trying to make "good points"...just help you guys out!

NO NO NO - DO NOT 'FLOOR' IT (untill you get it fixed !)

Obviously the fact that you hear "pinging" at ALL, ( with ANY commercially available "regular" gasoline) shows there is something VERY wrong with that portion of your car's ignition system controls, that control the spark advance.

You MUST NOT "FLOOR" it - soon as you hear significant pinging GET YOUR FOOT OFF THE GAS, THEN down-shft, and gradually feed in more throttle to suit your needs, but NOT enough to make it "ping".

"Pinging" is DESTRUCTIVE. It is telling you that the fuel inside your cylinders is EXPLODING, rather than burning in the nice "whoooof" that makes for mechanical power. The EXPLOSIONS that are "pings" WILL ruin your motor if you provoke it.

Yes, I know going to a factory-authorized dealer means they will charge you thru the nose. They arent there to run a charity ! The over-head, the high salaries, all means they WILL get into your wallet. DEEPLY. But that Is the way it is these days, with these modern computer-controlled cars. The cost of the computer analyzers (that connect to the OBD II "port" under your dash) is in the HUNDREDS of thousands of dollars. YOU must certainly will be paying for that when you get your bill. But you WILL waste time, money, and risk RUINING your motor by not taking care of this IMMEDIATELY at a COMPETENT Ford dealer who has the know-how, and the computer analyzers, to fix what is SERIOUSLY wrong with your V-10's ignition.

Good luck - and let us know what the service people tell you was wrong ! (and bring a box of tissues with you when you go pick your truck up...when you see the bill..you WILL be crying....a LOT ! )

 

yes..yes..my engine does not ping all the time..i make it do that by driving a low rpm under load..like going up a hill..it does not do it all the time..every vehicle i have ever owned pings every now and then..even my motorcycles when i used to ride..like i said..there could be a problem somewhere in teh system..you are telling me your engine never ..ever pings? are you sure?and floor it? me? never do that..even getting on the freeway..i am just a slow driver compared to the average person..i leave on time so i dont have to...and i know the opposite , that lugging always is bad also..not easy to do with a automatic transmission.
my ford escort that had 300,000 miles on it when i got rid of it, with the original clutch, again because of the way i drive..pinged alot with the cheap gas..but it stayed in tact somehow..you think if it was a bad as you say..i would have damaged a plug, broken the porcelin(sic..maybe) or caused other damage..my plugs when i changed them were fine..and they had 80,000 miles on them.
and you neglect to mention....but carbon deposits, wrong plug heat range or other factors may cause it also..not just low octane gas....and also piston and combustion chamber design..i assume the computer retards the timing if pre-ignition is detected by the sensors...until it stops...i just mentioned that because i read a thread long ago about that...anyway........im not worried in the least about my engine exploding from that issue...hummm..maybe its the tornado in my intake manifold or the splitfire plugs??

 

Thanks Fellows, pretty good explanation of octane. My truck has never "pinged". In my original post I talked about putting in 93 octane just because, you see, where I work, they have their own gas pumps and I can buy 93 gas a lot cheaper there then anywhere else in any public gas stations. So it's not a big deal to buy the 93 octane anytime I want to. Sometimes it is even cheaper then public stations 87 octane. That's why I wrote my post, Is it hard on the v10 to run 93 all the time?

 

Go to the V10 forum and read your heart out about pinging. It is very comon, and there are many causes for the "pinging". "flutter", transmission inspection plate, and heat shields are some none ignition causes of "pinging" noise. Read your heart out in the V10 forum. I have owned two V10s one that pinged and one that didnt. Not a big deal.

 

yes i remember reading about the flutter and heat shields..sorry..but i know its not a big issue if it was i think you'd know it after you holed your piston for broke a rod

 

Well, I have never heard my V-10 ping. I am also a very gentle driver. I only use 87 octane gas. No pings. Nope.

 

3:73's and 35/s my ex pings on winter fuel at 87 oct but the milage is always 3mpgs or better on 92 which depending on the stations price tiers for levels of gas is more economical and it is spark knock i can read the plugs tall tires tall gears and tall wieght make it pingat low rpms with the low overlap on the cams these dont bleed any cylinder pressure off at the low rpms. great for tourqe but terible for detination.