What's The Recommended Fuel Octane For The V10?is Anyone Getting Really Anymore Juice With The Higher Octanes,thanks

 

welcome to fte and our v10 area. no you do not need higher octane only the good old 87 blend. what many of us have found is using a good name brand or playing with different brands till we found what the motor liked around our area of the country helped more then a 89 or 92 blend .
fredvon 4 found chevron"ithink" to work best for him in texas. i'm in north west jersey and mine likes gulf here. try them all run what works best for you.
and good luck with your truck.

 

the manual states to use 85 octane minimum. 87 will work just fine for you.

 

What year is your V10? According to my 2003 manual it states that 87 min octane is recommended. It also states that using HIGHER octane fuel is NOT recommended for vehicles that were designed to use 87 octane.

It also says, "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."

biz

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2003 F250 SD SC 142" XLT FX4 V10 Auto 4x4 3.73s

 

I've been running 86 octane here in Colorado since I bought the truck new in late '98. It's a '99 and gets 13-14 MPH and if I'm pulling a load of horses over one of the passes, I will mix in a tank of 89 octane. I'm running a K&N filtercharger and low restriction exhaust.

 

welcome to our land of the mighty ford v10. and to fte.
it is interesting on how some of these motors run on a low octane fuel. esp. high up in the air where you are.
hang around and input with us.

 

Thanks For The Info Gang,appreciate It.

 

High performance engines usually have a very high compression ratio. 10:1, 10.5:1, 11:1 or higher up to around 12.7:1 is about the max before you get into serious mechanical trouble.

Our mod motors are centered in the 9:1, 9.2:1, and 9.4:1 compression ratio range.

The typical fuels today are rated in RON (Research Octane Number) between 85 and 93 "octane".

Fuel burns are a specific rate of speed. Mixed with differing amounts of air it can burn faster or slower. The compression ratio and fuel burn rate need to be synchronized so that the heat in the cylinder and the heat from compression do not make the fuel explode (burn real fast) before the right time for the descending piston to use the power of the explosion. If the air fuel mixture ignites too fast...the piston is not all the way to the top and starting down. When this happens we call it pre-ignition or detonation, in either case a bad thing. Pinging causes high frequency vibrations that destroy metals, bearings, and cause much mechanical grief.

The fuel's "Octane" is really an additive that slows down the speed the fuel burns at. More Octane, equals a slower burning fuel. To completely burn the higher octane fuel you need the higher compression and associated heat. These can be good qualities and build more power for a given cubic inches of motor but at the expense of higher wear, more costly fuel, and harsher power stroke on all the other drive line components.

The lower compression motors do the same amount of work in a slightly less explosive way and the fuel can have fewer additives and burn closer to it's natural rate. A lower compression ratio motor has a more even power stroke, creates less heat and stress, and is less prone to pre ignition, after run, and is an all around better long life application. But it can not maximize the thermal efficiency that is possible for it's cubic inches.. A compromise with most of the potential power but little or few of the bad side effects of max performance.

Burning high octane fuel in a low compression motor usually does not create enough heat to completely burn the fuel charge. The unburnt fuel, carbons up the cylinder walls, the rings, and pollutes the catalytic converter making it loose it's chemical efficiency.

It also lightens your wallet at a faster rate. This lighter wallet is the only way your truck will be any faster or get ever so slightly better MPG averages.

There are a few exceptions to ONLY running 87 octane...the clean air fuels with some additives are not the same as 87 when the mix is around 10% or 15% of the MTBE or whatever ethanol mix they are using. Some swear the clean air crap runs very good and some of us think it is crap. YMMV

ON a very hot outside air day and at altitudes over 5000 feet I have found that the mid grade runs better on my heavy towing days. This is because the 89-90 Octane stuff burns a little slower and this prevents the pre-ignition from the hot air and low air pressure and reduced oxygen content. Because it burns slower, and does not ping, then my computers do not detect any pinging and try to retard the timing, costing me power.

Hope this explains a little of what is all about low compression motors V10s, and octane ratings... this is not the whole story but enough with out getting into advanced chemistry

 

I wonder if mine runs good because it was programmed to the clean-air specs being it's setup for CA emissions? I always thought it ran sorta rich on the 100% gas I doubt they fine tune these things enough to make up for 10% ethanol...

 

Krewat... I gotta believe it is just regional. I have gotten a few loads of clean air fuel that I could feel the loss of power and not as peppy idle, almost a stumble and I knew it was the fuel. Other times I got a load of the stuff and it ran just fine. It also may be altitude related for me. Most of the time my truck lives here at 0~750 feet above sea level. The states I get the 10% ~15% mix clean air stuff are Colorado, Arizona, and in both of them I am usually above 4000 feet.

The CA emissions program in OBDII may also have a lot to do with it. So you might be right in that idea.

 

I thought I would chime in on this. My 2006 F-350 has its gas cap labeled "Ford recommends using BP gasoline". Out here in Washington the closest you'll get to BP is ARCO since that who own them. But my last V-10 ran like crap on that stuff. Strange. Most be a marketing deal.

 

That's funny... I run a cheapo gas from the Gulf station a few blocks away. They are by far, the cheapest around, but all my vehicles run GREAT on it.

If I go to BP (which recently changed hands), all my vehicles are noticably off, as in off-idle performance and even WOT, it acts like the motor is "cold", just as if I was running 93 octane instead of 87.

Weird....

By the way, the times I run 10% ethanol, I'm about 40 feet above sea level (Long Island = sandbar). The times I've gotten 100% gas, is around the 1000-2000 ft elevation, but I've come home with the 100% gas and driven around for a while, and still can't tell the difference when I fill back up with 10% ethanol.

Weird, weird, weird.

YMMV - literally!

 

I am not a fan of the v10 tri fuel but think the added sophistication for a true flex fuel smart sensor and PCM adaptation is a good idea...

My truck is not flex or LEV set up and thus the programs all expect a specific gravity? viscosity?, therms per liter? or what ever they programed based on 100 Dino with 87 RON... I am sure there is enough slop in the ramps to accommodate some variations of fuel characteristics and I know it can adapt well to altitude, humidity, temp,

Oh well I just wish the entire USA was on one fuel standard with three octane ratings...

 

While daily driving my 05, I averaged two tanks of 87 and then two tanks of 89 and the MPG with within .1 MPG of each other. No difference in running higher octane unless your towing through the mountains then the extra octane could reduce possible detonation. Knock sensors with pull timing in that event anyway, which would reduce power slightly.

 

I found that when I fuel up I get better mileage if I always buy from the same place out of the same pump. I think constantly switching brands and octanes messes with the computer and it takes awhile for it to truly fine tune everything. I run 89octane with 10% ethenol all the time and get 16 mpg avg at 55mph.